keyboard-shortcut-dialog: Separate each page into a GtkStackPage
requested to merge automerisnaranja/gnome-control-center:fix-adwstatuspage-keyboard-shortcuts-dialog into main
Doing so, it won't be necessary to use the vhomogenous property in GtkStack; same case for the vexpand property in AdwStatusPage.
There are also other minor fixes. See other commits for more details.
Edited by Automeris naranja