feat: Add support for color presets

They are stored in settings:
```
com.victronenergy.settings/
Settings/Gui2/Switchpane/Preset/RGB
Settings/Gui2/Switchpane/Preset/RGBW
Settings/Gui2/Switchpane/Preset/CCT
```

All of the settings are strings, holding 9 times 5 values in a comma separated format (5 values per preset: H,S,V,W,T)