#26630 wrap command callbacks to ensure exceptions bubble up in Maya

Because we use evalDeferred for stability on Linux, we've exposed a bug in Maya that causes any exceptions that are raised during the callback to get "stuck" and could potentially cause a crash. This works around the issue by wrapping the callback in a try/except clause and logging our own exception with the error and traceback info.
The `log_exception()` should already emit the full call stack so I would suggest doing something like:

```
except:
   self.log_exception("Executing one of the toolkit command resulted in an general error being reported.")
```

I think the fact that you are using the `log_exception` means you don't need to worry about any exception details!