Fix crack on animated tiles

[cx384]

• Fixes Crack overlay does not work for animated nodes #5317
• It adds a map to the map block mesh, which contains information about the animated crack mesh buffers, and removes it from the maps for crack and animated nodes, such that it can be updated separately when the animation frame/crack frame changes.
• It concatenates the crack string every time and does not cache it, like it is the case for non animated crack tiles.
  I suppose this is fine since there is only one cracked node at once.

To do

Ready for Review.

How to test

Start devtest, get some "Animated Test Node" (testnodes:anim) and dig them.

[cx384]

This is now set to the current frame and not to the first frame.
In the crack case I noticed flickering which can be fixed this way.
I guess for non crack tiles, it is not noticeable since the map block mesh gets updated rarely, but it is probably still better to use the current frame.

[sfan5]

Not that I want to say we shouldn't merge finished code, but with outlook on texture atlasing I think it would be good to redesign the crack rendering entirely.

[cx384]

I agree, the crack (and tile animation) rendering should be redesigned, i.e. done by a shader, but I suppose this will not happen anytime soon, and this bug is very old. So I think it is still worth fixing it in our current implementation.