Allow using ctrl+tab for tab switching
Currently in GTK4 it doesn't seem to be possible to use ctrl+tab
/ctrl+shift+tab
for switching tabs, like Firefox/Chrome/Safari/other browsers do (as well as GTK3 libhandy tabs and all apps using those). It'd be good to change this, so we can keep using this cross-platform standard shortcut that lots of people have muscle memory for.
cc @exalm