Create `record` command for `azpysdk` CLI

We should support recording both tests and samples via a `record` verb in the `azpysdk` CLI. For example:

```python
# Record pytest tests
azpysdk record test /path/to/test_file.py

# Record pytest tests with arguments
azpysdk record test /path/to/tests/ --pytest-args -v -k "test_name"

# Record a code sample
azpysdk record sample /path/to/sample.py
```

This should use our existing test recording infrastructure, e.g. `@recorded_by_proxy`, and adjust the environment as necessary to support sample recording in cases where the tooling is `pytest`-dependent. If it makes sense to decouple `pytest` from our tooling in some places, we can do that as part of this effort. For example, recording files are currently determined based on the `PYTEST_CURRENT_TEST` variable; we can either set this ourselves for samples or find another approach.