This commit completely revamps the way that blocks are represented in memory at runtime.
Instead of being represented by legacy Mojang block IDs and metadata, which are dated, limited and unchangeable, we now use custom PM block IDs, which are generated from VanillaBlocks.
This means we have full control of how they are assigned, which opens the doors to finally addressing inconsistencies like glazed terracotta, stripped logs handling, etc.
To represent state, BlockDataReader and BlockDataWriter have been introduced, and are used by blocks with state information to pack said information into a binary form that can be stored on a chunk at runtime.
Conceptually it's pretty similar to legacy metadata, but the actual format shares no resemblance whatsoever to legacy metadata, and is fully controlled by PM.
This means that the 'state data' may change in serialization format at any time, so it should **NOT** be stored on disk or in a config.
In the future, this will be improved using more auto-generated code and attributes, instead of hand-baked decodeState() and encodeState(). For now, this opens the gateway to a significant expansion of features.
It's not ideal, but it's a big step forwards.
while this is a bit hacky outside of the protocol namespace, it makes it much easier to use the protocol library for alternative purposes, such as for a client or MITM proxy.
It also removes all but one remaining core dependency of the protocol library, making it very close to being able to be separated from the server core entirely.
since a while ago, we're anyway just discarding the internal buffer anyway when the packet is repeatedly encoded, so this doesn't serve any advantage anymore.
We do need a system to be able to reuse encoded packet buffers, but right now we're not reusing them anyway.
this is not complete yet, but the final change (having the binarystream actually come from outside) is a little more disruptive, and some extra changes need to be made. This will grant some sanity in the meantime without breaking too much stuff.
