Projection does not count as PCU

[viktor-ferenczi]

See in MultigridProjection.InitializeClipboard:

// Based on the original code, but without taking up PCU for the projection

The relevant code is marked as INCOMPLETE_UNTESTED. It needs to be finished based on the original code, then enabled. Alternatively it needs to be turned into a transpiler patch to preserve the original code as much as possible.

If this code is finished then the grid PCU needs to be decreased in RemoveProjection, otherwise it builds up as subsequent projections are enabled.

It should also be made optional with a plugin configuration, because some admins may allow for over-limit PCU projection, while others don't. Building blocks over the PCU limit is not possible anyway. Blocking such projections would block loading a repair projection if the remaining PCU to the limit is less than the PCU of the ship, for example.