feat: standalone errors go.mod (cosmos#10779)

## Description

This PR:
* moves all of the `types/errors` code to a new `errors` go module, except:
  * the `RootCodespace` errors in `types/errors` stay there
  * ABCI stuff that depends on tendermint stays in `types/errors
* adds aliases to everything in `types/errors` referencing `errors` so **this is not a breaking change**

This will allow standalone go modules to use the same error types as the SDK. In particular, I want the `orm` to reference `errors` and then the SDK will be able to import `orm` and it can stay standalone. The same could apply to the `db` module.

After this PR the plan is to:
* tag `github.com/cosmos/cosmos-sdk/errors` as `v1.0` 🎉 
* remove the `replace` directive for `errors` in the main SDK `go.mod`

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [x] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

.gitignore

@@ -55,3 +55,5 @@ dependency-graph.png
 *.aux
 *.out
 *.synctex.gz
+/x/genutil/config/priv_validator_key.json
+/x/genutil/data/priv_validator_state.json

CHANGELOG.md

@@ -150,6 +150,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (types) [\#10630](https://github.com/cosmos/cosmos-sdk/pull/10630) Add an `Events` field to the `TxResponse` type that captures _all_ events emitted by a transaction, unlike `Logs` which only contains events emitted during message execution.
 * (deps) [\#10706](https://github.com/cosmos/cosmos-sdk/issues/10706) Bump rosetta-sdk-go to v0.7.2 and rosetta-cli to v0.7.3
 * (module) [\#10711](https://github.com/cosmos/cosmos-sdk/pull/10711) Panic at startup if the app developer forgot to add modules in the `SetOrder{BeginBlocker, EndBlocker, InitGenesis, ExportGenesis}` functions. This means that all modules, even those who have empty implementations for those methods, need to be added to `SetOrder*`.
+* (types/errors) [\#10779](https://github.com/cosmos/cosmos-sdk/pull/10779) Move most functionality in `types/errors` to a standalone `errors` go module, except the `RootCodespace` errors and ABCI response helpers. All functions and types that used to live in `types/errors` are now aliased so this is not a breaking change.
 
 ### Bug Fixes
 

errors/CHANGELOG.md

@@ -0,0 +1,40 @@
+<!--
+Guiding Principles:
+
+Changelogs are for humans, not machines.
+There should be an entry for every single version.
+The same types of changes should be grouped.
+Versions and sections should be linkable.
+The latest version comes first.
+The release date of each version is displayed.
+Mention whether you follow Semantic Versioning.
+
+Usage:
+
+Change log entries are to be added to the Unreleased section under the
+appropriate stanza (see below). Each entry should ideally include a tag and
+the Github issue reference in the following format:
+
+* (<tag>) \#<issue-number> message
+
+The issue numbers will later be link-ified during the release process so you do
+not have to worry about including a link manually, but you can if you wish.
+
+Types of changes (Stanzas):
+
+"Features" for new features.
+"Improvements" for changes in existing functionality.
+"Deprecated" for soon-to-be removed features.
+"Bug Fixes" for any bug fixes.
+"Client Breaking" for breaking Protobuf, gRPC and REST routes used by end-users.
+"CLI Breaking" for breaking CLI commands.
+"API Breaking" for breaking exported APIs used by developers building on SDK.
+Ref: https://keepachangelog.com/en/1.0.0/
+-->
+
+# Changelog
+
+## v1.0.0
+
+### Features
+* [\#10779](https://github.com/cosmos/cosmos-sdk/pull/10779) Import code from the `github.com/cosmos/cosmos-sdk/types/errors` package.

errors/abci.go

@@ -0,0 +1,129 @@
+package errors
+
+import (
+	"fmt"
+	"reflect"
+)
+
+const (
+	// SuccessABCICode declares an ABCI response use 0 to signal that the
+	// processing was successful and no error is returned.
+	SuccessABCICode uint32 = 0
+
+	// All unclassified errors that do not provide an ABCI code are clubbed
+	// under an internal error code and a generic message instead of
+	// detailed error string.
+	internalABCICodespace        = UndefinedCodespace
+	internalABCICode      uint32 = 1
+)
+
+// ABCIInfo returns the ABCI error information as consumed by the tendermint
+// client. Returned codespace, code, and log message should be used as a ABCI response.
+// Any error that does not provide ABCICode information is categorized as error
+// with code 1, codespace UndefinedCodespace
+// When not running in a debug mode all messages of errors that do not provide
+// ABCICode information are replaced with generic "internal error". Errors
+// without an ABCICode information as considered internal.
+func ABCIInfo(err error, debug bool) (codespace string, code uint32, log string) {
+	if errIsNil(err) {
+		return "", SuccessABCICode, ""
+	}
+
+	encode := defaultErrEncoder
+	if debug {
+		encode = debugErrEncoder
+	}
+
+	return abciCodespace(err), abciCode(err), encode(err)
+}
+
+// The debugErrEncoder encodes the error with a stacktrace.
+func debugErrEncoder(err error) string {
+	return fmt.Sprintf("%+v", err)
+}
+
+// The defaultErrEncoder applies Redact on the error before encoding it with its internal error message.
+func defaultErrEncoder(err error) string {
+	return Redact(err).Error()
+}
+
+type coder interface {
+	ABCICode() uint32
+}
+
+// abciCode tests if given error contains an ABCI code and returns the value of
+// it if available. This function is testing for the causer interface as well
+// and unwraps the error.
+func abciCode(err error) uint32 {
+	if errIsNil(err) {
+		return SuccessABCICode
+	}
+
+	for {
+		if c, ok := err.(coder); ok {
+			return c.ABCICode()
+		}
+
+		if c, ok := err.(causer); ok {
+			err = c.Cause()
+		} else {
+			return internalABCICode
+		}
+	}
+}
+
+type codespacer interface {
+	Codespace() string
+}
+
+// abciCodespace tests if given error contains a codespace and returns the value of
+// it if available. This function is testing for the causer interface as well
+// and unwraps the error.
+func abciCodespace(err error) string {
+	if errIsNil(err) {
+		return ""
+	}
+
+	for {
+		if c, ok := err.(codespacer); ok {
+			return c.Codespace()
+		}
+
+		if c, ok := err.(causer); ok {
+			err = c.Cause()
+		} else {
+			return internalABCICodespace
+		}
+	}
+}
+
+// errIsNil returns true if value represented by the given error is nil.
+//
+// Most of the time a simple == check is enough. There is a very narrowed
+// spectrum of cases (mostly in tests) where a more sophisticated check is
+// required.
+func errIsNil(err error) bool {
+	if err == nil {
+		return true
+	}
+	if val := reflect.ValueOf(err); val.Kind() == reflect.Ptr {
+		return val.IsNil()
+	}
+	return false
+}
+
+var errPanicWithMsg = Wrapf(ErrPanic, "panic message redacted to hide potentially sensitive system info")
+
+// Redact replaces an error that is not initialized as an ABCI Error with a
+// generic internal error instance. If the error is an ABCI Error, that error is
+// simply returned.
+func Redact(err error) error {
+	if ErrPanic.Is(err) {
+		return errPanicWithMsg
+	}
+	if abciCode(err) == internalABCICode {
+		return errInternal
+	}
+
+	return err
+}

types/errors/abci_test.go → errors/abci_test.go

@@ -34,14 +34,14 @@ func (s *abciTestSuite) TestABCInfo() {
 			debug:     false,
 			wantLog:   "unauthorized",
 			wantCode:  ErrUnauthorized.code,
-			wantSpace: RootCodespace,
+			wantSpace: testCodespace,
 		},
 		"wrapped SDK error": {
 			err:       Wrap(Wrap(ErrUnauthorized, "foo"), "bar"),
 			debug:     false,
 			wantLog:   "bar: foo: unauthorized",
 			wantCode:  ErrUnauthorized.code,
-			wantSpace: RootCodespace,
+			wantSpace: testCodespace,
 		},
 		"nil is empty message": {
 			err:       nil,