Fix type annotations and add missing logging statements

[Jineshbansal]

Description

This issue addresses code quality improvements:

1. Fix type annotations in QUICErrorContext.__exit__
2. Fix unnecessary return statement in Mplex.send_message
3. Add missing logging statements in Mplex message handling

Motivation

• Type safety: Current type annotations have errors (| None | None duplicate, Any instead of TracebackType)
• Code clarity: Unnecessary return and # type: ignore comments reduce readability
• Debuggability: Missing logging makes it hard to diagnose mplex stream issues in production

Current Implementation

QUIC exceptions (Line 354):

• exc_type: type[BaseException] | None | None - redundant | None
• exc_tb: Any - should be TracebackType | None

Mplex (Line 199):

• return await self.write_to_stream(_bytes) # type: ignore
• Unnecessary return since write_to_stream returns None

Mplex logging (Lines 280, 304, 310):

• 3 TODO comments for missing logger.warning() calls
• Logger already exists in file, just needs the calls added

Are you planning to do it yourself in a pull request ?

Yes