Add ability to define compose key and alternate key from gnome settings

[SoumyaRanjanPatnaik]

Possibly related, I also updated from 22.04 to 24.04 and in a Sway session, the compose key doesn't seem to work either, even though it is set via the gnome settings manager.

I always have to swaymsg 'input * xkb_options compose:menu' as described here, for me gnome settings never took any effect in sway.

Originally posted by @karlsebal in regolith-linux/regolith-desktop#1025 (comment)

[edelmanjm]

Really dumb, but is this also an issue with the default picom compositor? Setting the compose key in Settings → Keyboard doesn't seem to work for me.