Support camera ray collision for indented cubes

[westernheld]

Describe the bug
The collison detection is just working if the camera ray hits a solid cube. Fragmented cubes will be ignored. This will have different impacts depending on the situation:

1. Just one fragment before the void: No collision at all
2. A fragment in front of a full cube: The collision will detect the full cube, not the fragment in front of it.

To Reproduce
Steps to reproduce the behavior:
Go to a fragmented cube and see the console log.

Expected behavior
Make collision work with all possible conditions of a cube. Solid and fragmented.

Screenshots
No collision at fragment in lower left corner

Collision with a solid cube slightly above the fragment

Inexor Version: b0b2c46

[IceflowRE]

Removed cat:bug as this was an intentional decision. Nonless it should also work with indented cubes.

[IAmNotHanni]

This is #423