PyQt: handle ESC, BACKSPACE, C-x and C-c on key press
PyQt: handle ESC, BACKSPACE, C-x and C-c on key press

We can't catch them from the QWidget window by overriding
KeyPressEvent, nor from a custom QWebEngineView overriding
KeyPressEvent.

Qt filters didn't catch them either.

https://stackoverflow.com/questions/56890831/qwidget-cannot-catch-escape-backspace-or-c-x-key-press-events

jmercouris/NeXT,jmercouris/NeXT