find*NeighborList do not allow for ghost region

[aprokop]

Applications like Cabana often work in a distributed setting, where the set of local points is supplemented by the ghost ones. In those situations, the goal is to find the neighbors only for local points, but the search is done over both local and ghosts.

Our current interface for finding neighbors does not support this mode, as we only allow the same points for construction and search.