Add default settings for Breeze GTK
There are three default settings provided by the theme:
- Cursors default to Breeze under Breeze GTK.
- GTK modules default to the colour reloading module (not landed, but will fallback gracefully) and the appmenu module.
- Error bell is defaulted to off as under most Plasma environments the bell results in the PCSPKR chiming, and Qt applications don't chime the PCSPKR when GTK does.