Blender Git Loki

IDManagement: Collection: Fix several issues in relationships building code.

`BKE_main_collections_parent_relations_rebuild`,
`BKE_collection_parent_relations_rebuild` anf their internal
dependencies had two issues fixed by this commit:

* Main one was that a same collection could be processed several times,
sometimes even in an infinite loop (in some rare corner cases), by
`collection_parents_rebuild_recursive`.
* More exotic, code here would not ensure that the collections it was
processing were actually in Main (or a master one from a scene in
Main), which became an issue with some advanced ID management
processes involving partially out-of-main remapping, like liboverride
resync.