When the commit string from the inputMethodEvent can be interpreted as
characters bound to some action, dispatch this action instead of
inserting the string.
This is useful on an international keyboard, when diaresis+space gives
a plain double quote. It is better in this case to enter a smart
quote.
Adapted from a patch from Daniel Ramoeller <d.lyx@web.de>.
Fixes bug #10377.
Fixes: #11508
Now there is the opposite case which needs to be addressed:
If no translation is available for a shortcut in a non-latin-scripted
document, we need to switch the language to English.
