Rewrite for Fabric 1.15.1

[EngiN33R]

• Rewrite codebase for Fabric 1.15.1

• Adjust Gradle build config for Fabric build process

• Remove unused and archived assets

[EngiN33R]

To contribute my thinking concerning libraries: the Fabric ecosystem is different from Forge, especially in its modularity. The ecosystem consists of tightly interwoven libraries used in mods to provide extra functionality without pulling in a large amount of unnecessary code, as opposed to Forge's philosophy of having a monolithic all-you-can-eat solution and only using a subset of the features.

While it could be argued that LibGui is not strictly necessary, and vanilla Minecraft code could be adapted to serve its purpose, NbtCrafting is a core dependency enabling crafting recipes with NBT data, which is functionality that would require a non-trivial amount of labour to replicate.

Being libraries widely used in the Fabric ecosystem, it is a guarantee in practice that these libraries, or projects that provide compatible functionality, will continue existing and being updated to fulfil the needs of other mods, and the probability of us being left stranded without a library update is relatively slim. From the end user side, these libraries will not have to be installed as dependency mods and updated, as they are packaged directly in the mod JAR.

[RainbowTabitha]

Can we merge this soon?