[Feature] Simplify pbio color light interface

[laurensvalk]

This is a note for future consideration as we might not get to it now. The system light interface seems to have evolved to be a bit more complicated than it perhaps needs to be.

It seems to be currently:

user --> pbsys_instance.pbio_light --> pbsys callback --> pbio --> pbdrv

I suppose it could be:

user --> pbsys --> pbio --> pbdrv

The intermediate pbsys layer here would fulfill a similar role as in the current approach, to disallow user updates when a system light pattern is active.

Also, since the fading run animation is not really a system pattern but a (default) "user animation", it can perhaps also be taken out of pbsys, and just get initiated when the user color light is instantiated. This would also allow the user to .reset() the light to this state, which is currently not possible.