PlayerStart in LevelInstance are not loaded early enough in PIE as Standalone/Listen

Non-spatially loaded actors in a Level Instance are not embedded properly when entering PIE. This issue does not happen in a cooked build.

• Make new empty world partition level (with just a plane or something so it isn't massive)
• Add a player start, on top of a cube or something
• Observe that you will start there in PIE (Standalone, Listen, Client), as well as a cooked build
• Collapse that player start into a level instance (ofpa, non-streaming)
• Observe that Standalone/Listen pie now starts at the origin, while PIE+Client as well as a cooked build still work correctly