Lifetime checks for stored `RIDs` for collision objects assumed they had valid `object_ids`.
It turns out that some are not derived from `Object` and thus checking `ObjectDB` returns false for some valid `RIDs`.
To account for this we only perform lifetime checks on valid `object_ids`.
When travel is high enough, keep the global position resulting from the
move_and_collide call, and set the motion to the remainder from the
move_and_collide call. This ensures travel is taken into account once,
rather than twice.
Physics body previously stored the RID of a collision object and accessed it on the next frame, leading to a crash if the object had been deleted.
This PR checks the object still exists via the ObjectID prior to access.
