A Param should never be directly used to satisfy a Get (pantsbuild#9890)

### Problem

As described in pantsbuild#9878, we observed a case where a `Param` was being used to direct satisfy a `Get`. But this runs afoul of an invariant that has been in place for a while now that the "provided" `Param` (ie the "input" to the `Get`) must be consumed by the subgraph below the `Get`.

The reasoning behind this invariant is that when a user uses a `Get`, the intent is always for the input `Param` to be used in that computation. And that holds in this case.

### Solution

Extract `RuleGraph` building into a separate module, and then add two tests of cyclic behavior: one that was already passing, and another that described the situation in pantsbuild#9878, and which was failing. Finally, enforce the invariant for `Params` (as it was already being applied to `WithDeps` entries: ie, `@rules`) to fix the test.

### Result

Fixes pantsbuild#9878.

src/python/pants/engine/internals/scheduler_test.py

@@ -113,8 +113,10 @@ class UnionX:
 
 @rule
 async def error_msg_test_rule(union_wrapper: UnionWrapper) -> UnionX:
-    union_x = await Get[UnionX](UnionWithNonMemberErrorMsg, union_wrapper.inner)
-    return union_x
+    # NB: We install a UnionRule to make UnionWrapper a member of this union, but then we pass the
+    # inner value, which is _not_ registered.
+    _ = await Get[A](UnionWithNonMemberErrorMsg, union_wrapper.inner)
+    raise AssertionError("The statement above this one should have failed!")
 
 
 class TypeCheckFailWrapper:
@@ -176,7 +178,7 @@ def rules(cls):
             transitive_coroutine_rule,
             RootRule(UnionWrapper),
             UnionRule(UnionBase, UnionA),
-            UnionRule(UnionWithNonMemberErrorMsg, UnionX),
+            UnionRule(UnionWithNonMemberErrorMsg, UnionWrapper),
             RootRule(UnionA),
             select_union_a,
             UnionRule(union_base=UnionBase, union_member=UnionB),

src/rust/engine/engine_cffi/src/lib.rs

@@ -51,7 +51,7 @@ use hashing::{Digest, EMPTY_DIGEST};
 use log::{self, error, warn, Log};
 use logging::logger::LOGGER;
 use logging::{Destination, Logger, PythonLogLevel};
-use rule_graph::RuleGraph;
+use rule_graph::{self, RuleGraph};
 use std::any::Any;
 use std::borrow::Borrow;
 use std::convert::TryInto;