More verbose tracebacks on exceptions in event loop

When an exception happens during the event loop, only a tight traceback is printed.

  File "D:\tmp\tox\py39-PyQt5-all\lib\site-packages\napari\utils\events\containers\_evented_list.py", line 195, in insert
      self.events.inserted(index=index, value=value)
    File "D:\tmp\tox\py39-PyQt5-all\lib\site-packages\napari\utils\events\event.py", line 763, in __call__
      self._invoke_callback(cb, event if pass_event else None)
    File "D:\tmp\tox\py39-PyQt5-all\lib\site-packages\napari\utils\events\event.py", line 801, in _invoke_callback
      _handle_exception(
    File "D:\tmp\tox\py39-PyQt5-all\lib\site-packages\napari\utils\events\event.py", line 788, in _invoke_callback
      cb(event)

But it is often not very helpful to debug.

pytest support rich tracebacks https://docs.pytest.org/en/7.1.x/how-to/output.html#modifying-python-traceback-printing

Will you accept PR with such enhancement?

Start by reading napari's event.py around _invoke_callback and _handle_exception, with _evented_list.py showing the reported traceback path. Compare the current exception output with pytest's rich traceback documentation. Done means exceptions raised during the event loop provide a more useful, verbose traceback, with coverage for the changed behavior.