To prepare for translation support, this makes all of the widgets
cognizant of the language change event that occurs whenever
installTranslator() is called and automatically retranslates their text
where necessary.

This is important as calling the backing UI's retranslateUi() is often
not enough, particularly in cases where we add our own strings that
aren't controlled by it. In that case we need to manually refresh the
strings ourselves.

Allows removing the inclusion of the main input common header from the
UI config header.

Prevents compiler warnings related to truncation when invoking the
dialog. It's also extremely suspect to use a u8 value here instead of a
more general type to begin with.

The common pattern is to put the data members after the function
interface where applicable.

Handles button configuration for all controller layouts and debug pads. Configurable at construction.