[scx-layered] add capability to have a layer track gpu accessing tasks

[likewhatevs]

I'm throwing this idea out there to see if folks have ideas around how to implement it.

I want the ability to somewhat auto-magically have all threads that have touched a GPU be added to a layer in layered.

I think the right way is to add an additional match that is "has touched GPU", which can then be combined with other filters to enable flexibility in matching/prioritizing things.

I need to look at what is in common, but I kind of think wrapper fn's around nvml (which we would use for this) should go there if any are needed.

[likewhatevs]

@valentinandrei @htejun @hodgesds any thoughts about this? I know we had a couple kind-of starts wrt/ adding more-comprehensive gpu support like this in fall but I think now's the time, idk.