Refactor _wrap_callback timeout and body handling with match

[adamtheturtle]

Summary

Refactor _wrap_callback’s inner function in decorators.py to use match for timeout normalization and request body → bytes conversion.

Precise location

• File: src/mock_vws/_requests_mock_server/decorators.py
• Method: MockVWS._wrap_callback → nested wrapped
• Lines: approximately 170–186

Branch 1: timeout from req_kwargs

• isinstance(timeout, tuple) → use read component timeout[1]
• Then isinstance(timeout, (int, float)) → effective = float(timeout)

Candidate: match timeout: with case tuple():, case int() | float():, case _: effective = None (preserve current semantics).

Branch 2: request.body

• None → b""
• isinstance(raw_body, str) → UTF-8 encode
• Else → treat as bytes

Candidate: match raw_body: with case None:, case str():, case _: (bytes).

Acceptance criteria

• Delay / timeout / requests.exceptions.Timeout behavior unchanged.
• Existing tests pass.