Cubemap probes placement/lookup is incorrect

[VReaperV]

#1256 (comment):

The cubemap search function can only find probes that are in the same epsilon X epsilon X epsilon-sized voxel. 0.01 is unreasonably small so I assume it was inverted by mistake. 100 is still too small for it to find one the majority of the time though. Overall the code really doesn't make any sense, since the probes are generated in an irregularly spaced way according to BSP nodes, but the lookup code seemingly expects them to be evenly spaced like the light grid, or at least placed with a minimal density.

This should be evaluated at some point, but the cubemap reflections themselves should be fixed first.

[VReaperV]

Here's an example of how the current placement works on plat23:

[VReaperV]

This will be fixed once #1355 is merged.