Add LOD support to Object Paging

Currently, LODs do not switch correctly, this issue is most noticeable in the active grid where transitions are quite literally in your face. The expected behavior is to switch an LOD once it reaches a distance threshold, but this behavior is wildly inaccurate when using paging.

Reproducing:

1. Enable active grid OP
2. Download test.zip and add as a data directory
3. Load the included Quicksave.omwsave and approach the log

You should see the LOD switch, but it does not for the log.

Active grid enabled:

Active grid disabled:

This sounds like it should be a duplicate issue but I couldn't find one. Incorrect behavior in 0.47 release and master (d2f44706) so I don't believe it's a regression.