Rename `theta_cuts` arguments to `spatial_selection_table`

> Also, this is more in line with the fact that we don't use the term "_point-like IRFs_" anymore, and instead use "_SpatialSelection=None | RAD_MAX_"

_Originally posted by @kosack in https://github.com/cta-observatory/ctapipe/pull/2473#discussion_r1916226869_
            