Add paramtype2s for 4 horizontal rotations and 64 colors

[Wuzzy2]

Fixes #6194. @VanessaE. @paramat. @C1ffisme. @Sokomine.

This PR adds 2 paramtype2s: 4dir and color4dir.

4dir is like facedir, but only for 4 horizontal directions: NESW. It is identical in behavior to facedir otherwise. The reason why game makers would want to use this over facedir is 1) simplicity and 2) you get 6 free bits.
It can be used for things like chests and furnaces and you don't need or want them to "flip them on the side" (like you could with facedir).

color4dir is like colorfacedir, but you get 64 colors instead of only 8.

Also, as with all color paramtype2s, the builtin functions were updated accordingly.

For details on how this works, see the commits (lua_api.txt). Documentation for facedir and wallmounted is also updated to distinguish those better from 4dir.

To do

This PR is ready for review.

Many test cases in DevTest were added which I used for testing in depth. I tested rotation (obviously), color, falling node, and all new nodes I added to DevTest. I also tested the new and modified builtin functions (but you should, too!). It all seems to work to me.

One thing I didn't test in depth is the prediction. I am not so sure if the placement prediction code is correct, please some verify the logic. I don't know how test this part. It would also help me if you have a hint for me on how I can test predition better (I think I basically need to simulate a lag or something ...).

How to test

Use DevTest and use the many 4dir nodes and the Param2 Tool to modify them. Compare with facedir param2 values 0 to 3, it MUST look the same.
Test if the nodes still look OK when falling (use Falling Node Tool).
Use DevTest and luacmd mod to test all the functions I modified.

Use cases

• Colored and rotatable chests
• Colored and rotatable beds
• Colored and rotatable stairs (as long you don't also want upside-down stairs)

[hecktest]

How about calling it coloryaw since it's just around the Y axis?

[Wuzzy2]

I don't really care either way. It depends on what others think. If enough people are for it, I change it. If not, then not.

[Wuzzy2]

Note: This PR should have a concept approval because #6194 is "supported by core dev".

[Wuzzy2]

Bump.

[SmallJoker]

Rebase needed.

[Wuzzy2]

Rebased.

[ghost]

Starting to look at this today. Haven't seen anything too out of the ordinary, but haven't done much with it yet.
From a first look, this seems fine:

[ghost]

Did some further testing, including a test of round-tripping various vectors through dir_to_fourdir and fourdir_to_dir, no issues on that end.

[Wuzzy2]

@Df458: Done.

[ghost]

Looks good to me now

[Zughy]

@Wuzzy2 please rebase

[Wuzzy2]

@Zughy: Rebase complete!

[x2048]

Tested and reviewed, but a rebase needed. I've pushed rebased branch here.

@Wuzzy2

[Wuzzy2]

Rebase done. Testing needed.

[Zughy]

@Wuzzy2 please either remove the label by yourself or quit from being a triager, this is not the first time it happens

[Wuzzy2]

Follow-up PR for Minetest Game: #2992