Add logging parameter to retry decorator for automatic retry logging

Currently, logging retry attempts with tenacity requires manually wiring before, after, and retry_error_callback hooks every time. This is verbose and repetitive for a common use case.
Proposal: Add an optional logging parameter to the retry decorator that automatically sets sensible callbacks using stdlib logging:
```
python@retry(stop=stop_after_attempt(3), logging=True)
def my_function():
...
```
This would log:
- Each retry attempt (attempt number, wait time)
- The final exception if all attempts fail

The existing before/after/retry_error_callback hooks remain unchanged, this is purely additive as a convenience wrapper over them.

Motivation: Similar to how requests integrates with logging automatically, this would make tenacity friendlier for production use without any breaking changes.

Start at the retry decorator and inspect how the existing before, after, and retry_error_callback hooks are configured and invoked. Define the optional logging parameter without changing those hooks, then verify that retry attempts and the final exception are logged with the requested details and that existing behavior remains unchanged.

Written by the indexing model from the issue text.