Now using the Collector to allocate a one frame resource so this stays alive.
#rb daniel.wright
#jira UE-67857
[CL 4685499 by Matt Collins in Dev-Rendering branch]
#rb none
Contains temporary removal of some FGeometryCollectionSceneProxy code that is not compatible with refactor.
[CL 4664599 by Marcus Wassmer in Dev-Rendering branch]