Add dask+cupy (cuda) implementation for Aspect (and other convolutions)

[relativityhd]

I tried implementing it by myself for the aspect, it seems to work just fine:

def _run_dask_cupy(data: da.Array) -> da.Array:
    data = data.astype(cupy.float32)
    _func = partial(_run_cupy)
    out = data.map_overlap(_func,
                           depth=(1, 1),
                           boundary=cupy.nan,
                           meta=cupy.array(()))
    return out

So is there any reason I am not aware of why this is disabled / not implemented?

[brendancol]

@relativityhd Great Question and point! Any chance you could submit a PR for that and I'll prioritize review and merging