GNOME 45 support

[saltyming]

Would you mind adding support for gnome-45?

[titaniumbones]

I believe it's a bit more involved than it has been in other recent releases:
https://blogs.gnome.org/shell-dev/2023/09/02/extensions-in-gnome-45/

I don't think it's incredibly difficult, but I haven't written JavaScript for a while and when I did do these conversions, it was always a bit more fiddly than I expected.

If someone does manage to modify the code, it'd be fantastic if you posted the branch here so the rest of us cna pull.

[velitasali]

Hi! I started working on this. The extension now works, but the preferences window needs to be ported to AdwPreferencesPage. I will finish that in a few days. Thank you!