Create a new Blender collection or get an existing one.
A collection that doesn’t exist yet is created and linked to the active scene’s collection. An existing collection is returned without changing where it is linked, unless a parent is given.
The collection to link the collection into, which also unlinks it from the scene’s collection. A string is the name of the parent collection, which is created and linked to the scene if it doesn’t exist. Default is None, which leaves the collection where it is.