Portals - fix PVS generation and move settings

[lawnjelly]

Fixed a bug in the complex PVS generation which was causing recursive loop, and changes the default method back to using this complex method.
Move some of the settings out of RoomManager into Project Settings.
Allow PVS generation method to be selected from Project Settings, and control PVS logging.

Notes

• While initially this was a bug fix for the complex PVS generation I decided at least for the betas it would be nice to expose choosing the PVS method, and whether PVS generation logs were displayed.
• I had another look at the properties of RoomManager and thought it might be better to move some of them (that are unlikely to change during runtime) into ProjectSettings in order to keep the RoomManager as simple as possible.
• In most cases, users won't need to tweak these ProjectSettings anyway, so it makes sense to keep them hidden.

[akien-mga]

Thanks!