Add missing type annotations and fix typing inconsistencies

[ChihweiLHBird]

• Add parameter type annotations to parse_forwarded, parse_xforwarded, _compare, AcceptList.match, and parse_credentials in sanic/headers.py
• Use TYPE_CHECKING guard for Header and Config imports to avoid circular imports
• Fix variable reuse in parse_forwarded where header was reassigned from list to str (renamed to header_values)
• Change parse_credentials prefixes param from list | tuple | set | None to Collection[str] | None, and remove now-redundant isinstance runtime check that conflicted with the type annotation
• Add element type to _run_shell_command(command: list[str]) in scripts/release.py
• Fix import formatting in test files

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.730%. Comparing base (785d77f) to head (e1109ff).

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #3152       +/-   ##
=============================================
- Coverage   87.793%   87.730%   -0.063%     
=============================================
  Files          105       105               
  Lines         8143      8142        -1     
  Branches      1290      1290               
=============================================
- Hits          7149      7143        -6     
- Misses         687       692        +5     
  Partials       307       307               

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