[Feature] Sign rework api (part 1 of 2 for sign rework PR)

[DerToaster98]

Describe in detail what your pull request accomplishes

As discussed with @oh-noey the original PR (#679 ) is being splitted into two parts. The first part (this PR) being the necessary API classes and changes ONLY.

That contains the base classes for all signs as well as their registration and the sign wrapper shenanigans.

This does not yet contain the necessary changes to TranslationTask.java and RotationTask.java as those changes need to be looked at again. Most of the change is switching to a call to the signListener instance though.

Checklist

• [ ] Tested
• [ ] Performance tested (Could improve performance, but mainly makes the sign behaviors extendalbe and overridable in a nicer way. Also reduces duplicate code)

[DerToaster98]

I did an initial look through, to properly understand the AbstractMovecraftSign I think I'll need to try my hand at updating a sign or two.

For examples on the implementations you can just check the (older) PR which also has the implementations (#679 ) or the testbranch in my fork

[DerToaster98]

Adressed your points

[DerToaster98]

PR is ready for new review, it is now at the same state as my own testing branch which is being run since 2 weeks on a different server and so far works good