Implement Wayland support in Night Light applet

[JoshStrobl]

Night Light needs to be ported to wlr-gamma-control-unstable-v1 / budgie-daemon v2 / gammastep (as a quick hack).

The easiest route would be adding gammastep as a runtime dependency and starting / stopping gammastep with a one-off gamma set for our temperature value. Schedule is a bit trickier due to geoclue + MLS (Mozilla Location Services) being non-functional, so we would need to provide a setting in Budgie Control Center for setting your lat / lng instead.

Afterwards, we would port it to using budgie-daemon v2 when it supports its own SetGamma or SetTemperature on an output configuration object. This is expected to be implemented after the configuration batch system. At that point, the Night Light applet would just create new configuration objects to be applied that'd toggle it on / off or set temperature.