Previously a crude metric was used to decide on the roaming expansion margin, but it created unexpected results in some scenarios. Instead this setting is exposed to the user via the RoomManager, allowing them to tailor it to the world size, room sizes, roaming objects sizes and the speeds of movement.
The PVS mode enum had been declared using scope operator, which does not seem to work correctly from GDScript with the BIND_ENUM_CONSTANT macro.
This PR removes the scope operator in the declaration.
Fixed a bug in the complex PVS generation which was causing recursive loop.
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.
For the time being we don't support writing a description for those, preferring
having all details in the method's description.
Using self-closing tags saves half the lines, and prevents contributors from
thinking that they should write the argument or return documentation there.
(cherry picked from commit 7adf4cc9b5)
