Handle FAST003 aliases from Annotated type aliases

[ya-nsh]

Summary

• Teach FAST003 to resolve Annotated[..., Path(alias=...)] aliases through same-file type aliases.
• Scan all Annotated metadata entries so aliases are recognized when Path(...) is not the first metadata element.
• Add FAST003 regression coverage for direct aliased type aliases and multi-metadata aliases.

Related to #16795.

Test Plan

• cargo test -p ruff_linter --lib rules::fastapi::tests::rules::rule_fastapiunusedpathparameter_path_new_fast003_py_expects --features test-rules -- --nocapture
• cargo test -p ruff_linter --lib rules::fastapi::tests::deferred_annotations_diff::rule_fastapiunusedpathparameter_path_new_fast003_py_expects --features test-rules -- --nocapture
• cargo test -p ruff_linter --lib rules::fastapi::tests --features test-rules -- --nocapture
• cargo fmt --check
• uvx prek run --from-ref origin/main