[Development] State of QT_KEYPAD_NAVIGATION (QtWidgets)

[Christian Ehrlicher]

Hello,

recently I stumbled upon the QT_KEYPAD_NAVIGATION define in our widgets 
code. At first I was under the impression that this is defined by 
default similar to other features but this wasn't the case. Also I could 
not find a documentation for this and also no configure switch...
Therefore the only way to compile it with this option is to set it in 
CMAKE_CXX_FLAGS directly which I did but soon got compiler errors due to 
missing functions. They were removed (partly by accident I would guess) 
during the Qt6.0 deprecated stuff cleanup.

This means noone could compile this code since Qt6.0 but also noone 
complained about it. Therefore I would like to remove it completely but 
wanted to get some feedback if we maybe should try to fix the code 
instead (and convert it into a proper config option).


What do you think?

Christian