Improve comment handling around PatternMatchAs (#6797)

## Summary

Follows up on
https://github.com/astral-sh/ruff/pull/6652#discussion_r1300871033 with
some modifications to the `PatternMatchAs` comment handling.
Specifically, any comments between the `as` and the end are now
formatted as dangling, and we now insert some newlines in the
appropriate places.

## Test Plan

`cargo test`

crates/ruff_python_formatter/resources/test/fixtures/ruff/statement/match.py

@@ -168,6 +168,27 @@ match pattern_comments:
         pass
 
 
+match pattern_comments:
+    case (
+        pattern
+        # 1
+		as
+        # 2
+		name
+        # 3
+    ):
+        pass
+
+
+match subject:
+    case (
+        pattern # 1
+        as # 2
+        name # 3
+    ):
+        pass
+
+
 match x:
     case (a as b) as c:
         pass