Feature/moon celestial

[ShirleyNekoDev]

Adds logic for different sun textures (moon / custom) including moon phases.
Only in code at the moment including loading/saving into scene config, UI can be added later.
This was recently requested in Discord and in previous issues (#1208, #731).
based on top of #1654 (diff is way smaller)

[leMaik]

This needs a rebase after the recent refactorings.

[ShirleyNekoDev]

Should be ready now :)

This needs a rebase after the recent refactorings.

[leMaik]

Do we need to reset the moon texture after reloading the resource packs? wouldn't it be better to have a MoonPhaseTextureLoader that handles this?

[ShirleyNekoDev]

Do we need to reset the moon texture after reloading the resource packs? wouldn't it be better to have a MoonPhaseTextureLoader that handles this?

Yeah, probably a good idea to refresh the moon texture after a resource pack reload!
How would you expect the MPTextureLoader to work? I haven't had a look at this part of the code base for a while. Do you want to append it to this PR? :)