Handle selectors corresponding to key presses, such as cancelOperation:,
ourselves because we never get the keyDown events that are supposed to
take care of generating it from the native code somehow.
This fixes cancelling editing with Escape which stopped working since
26d6f82a81 (Implement EVT_CHAR generation for wxDataViewCtrl under Mac,
2021-04-13).
Closes #17835, #2639.
Co-Authored-By: Stefan Csomor <csomor@advancedconcepts.ch>