Boy this was hard.
To ease the pain of porting wireless-security to GTK4, add
a new WsFileChooserButton class that mimics the behavior of
a button that triggers a filechooser, as per the migration
guide suggests.
There were lots of GtkGrids, so the diff is particularly
horrendous. Sorry.
This needs serious testing before landing.
Setting markup within UI file might be bad as some translators
might break those markups.
Setting it in C source allows to exclude the markups from being
translated, and thus to not confuse translators.
642be83798 (note_608677)