Properly implement registries

[psu-de]

Registries contain version specific data and are used at a lot of places.

Registries contain a set of predefined data by default (the minecraft:vanilla datapack), but can be dynamically extended.
Currently, MinecraftData is our registry, it contains some (not all) data for the vanilla datapack and can't be extended.

Tasks:

1. The new Registry should be able to query everything from a MinecraftData instance, but also add the ability to extend the data. A registry lookup should only be done using Identifier's.
2. There is still a lot of data missing from MinecraftData. Mostly we require mappings from a minecraft version specific number used in the protocol, to a version independent identifier (for example at ParserRegistry). Minecraft-data doesn't provide most of this data, but mcmeta is looking very good for a new data source.