SetupPeriodicRayBCAction

Sets up the periodic boundaries for a PeriodicRayBC if applicable.

It acts on all RayBCs, but only operates on those that are a PeriodicRayBC.

A separate action is required for a PeriodicRayBC as ghosting needs to be setup before the PeriodicRayBC is constructed. This action sets up that ghosting and the libMesh::PeriodicBoundaries object needed by the boundary condition.