Add connected textures

[iijj22gg]

This adds a basic built-in resource pack that adds ctm

Currently, the ctm is state based and only includes the normal glass, with ctm added for all relevant partial textures. This was easy to do as a proof-of-concept.

This may require Continuity for everything other than full faces, since I don't think Optifine properly supports namespaces.

Also, I have never dealt with a mod's source before, so I have no idea how this works. I just put the resource pack in the same place that Continuity puts their built-in packs, and I haven't yet looked into how to build it.

Stuff to do:

1. Add ctm to stained and tinted glass. Requires new textures.
2. Test with Optifine
3. Add translations to pack description
4. Connect textures between specific blockstates. Requires many new textures and many properties files.

[CLAassistant]

All committers have signed the CLA.

[iijj22gg]

So... extracting the jar and putting the resource pack in the same place as I see built-in resource packs in other mods like Continuity does not work, so I assume it needs to be declared somewhere in the mod.
I tried building the mod to see if it happens automatically, but I can only get it to build for verision 1.21.3, and issue #46 exists

[Alexander01998]

Hey, first off thanks for the PR! I'll take a closer look soon but am kind of busy preparing for 1.21.4 right now.