[Python] Type annotation and Option handling improvement

[dbrattli]

• Fix string literal inlining for Python to prevent Pyright errors when accessing attributes on Literal types
• Add widen() helper to convert erased Option callbacks (T | None) to wrapped Option form (Option[T]) for type checker compatibility
• Improve interface/protocol generation with proper vararg handling and positional-only parameters
• Fix Dictionary Keys/Values to return proper IEnumerable wrappers
• Update type annotations to use Mapping instead of MutableMapping for IDictionary
• Support [<Global>] attribute in type annotations

[github-actions]

Python Type Checking Results (Pyright)

✅ All non-excluded files pass

Metric	Value
Excluded files	5

Files excluded from type checking

These files have known type errors and are excluded from CI. Remove from pyrightconfig.ci.json as errors are fixed.

temp/fable-library-py/fable_library/list.py
temp/tests/Python/fable_modules/thoth_json_python/encode.py
temp/tests/Python/test_applicative.py
temp/tests/Python/test_misc.py
temp/tests/Python/test_type.py