Fix bug where ensure_remote_portal_then_teleport() converted its destination_wormholePos to an anchorPos to pass to locate_or_build_portal() which converted it back to an wormholePos. Bug occurred when local_orientation was assumed for the target orientation, which could lead to locate_or_build_portal() ending up with a reconstituted wormholePos rotated outside the portal frame, not find a portal frame, so build a new portal there, griefing the old one.
locate_or_build_portal() has been refactored to take a wormholePos instead of an anchorPos, removing the need to know the orientation of the target portal (which can't be obtained from the param2 when the target portal is unlit)
This is effectively a missing part to the change that made locate_or_build_portal() enforce that portals only link together in mutual pairs. As target portals that didn't need to be located or built we not being updated to link back to where the player travelled from.
Also
* implements events: on_run_wormhole, on_extinguish
* adds a lot of debug info
