fix(fmt): match branch enum extra newline (FuelLabs#4084)

## Description

Closes FuelLabs#3131

Simple check to see if we already end with a newline - if we do, don't
write one.

We could probably have a helper fn that condenses this into one line to
make the `Format` impls take up less vertical space.

## Checklist

- [x] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [ ] I have requested a review from the relevant team or maintainers.

Co-authored-by: Joshua Batty <[email protected]>

Author: spiral-ladder

swayfmt/src/utils/language/expr/tests.rs

@@ -237,6 +237,42 @@ fmt_test!(  match_branch_kind
 quux();\n    }\n\n\n}"
 );
 
+fmt_test!(  match_branch_kind_tuple_long
+"match (foo, bar) {
+    (
+        VeryLongFoo::SomeLongFoo(some_foo),
+        VeryLongBar::SomeLongBar(some_bar),
+    ) => {
+        foo();
+    }
+    (
+        VeryLongFoo::OtherLongFoo(other_foo),
+        VeryLongBar::OtherLongBar(other_bar),
+    ) => {
+        bar();
+    }
+    _ => {
+        revert(0)
+    }
+}",
+            intermediate_whitespace
+"match (foo, bar) {
+    (
+        VeryLongFoo::SomeLongFoo(some_foo), \n  \n VeryLongBar::SomeLongBar(some_bar)) => \n 
+    \n{
+    \n
+        foo();
+    }
+    (VeryLongFoo::OtherLongFoo(other_foo), VeryLongBar::OtherLongBar(other_bar) \n ) => {
+        bar();
+    \n
+    }
+    _ \n=> {
+      \n  revert(0)
+    }
+}"
+);
+
 fmt_test!(  basic_array             "[1, 2, 3, 4, 5]",
             intermediate_whitespace " \n [ 1 , 2 , 3 , 4 , 5 ]  \n"
 );

swayfmt/src/utils/language/punctuated.rs

@@ -54,7 +54,9 @@ where
                     write!(formatted_code, " ")?;
                 }
                 LineStyle::Multiline => {
-                    writeln!(formatted_code)?;
+                    if !formatted_code.ends_with('\n') {
+                        writeln!(formatted_code)?;
+                    }
                     let value_pairs_iter = self.value_separator_pairs.iter();
                     for (type_field, comma_token) in value_pairs_iter.clone() {
                         write!(