Snapshot support

This adds support for all snapshots between 0 (13w41b) and the current head (1.16.2 as of writing this MR)

This is heavily WIP, I'll update this MR once complete.

Added/changed:

• Deleted ProtocolVersion enum (work with protocol version numbers): Versions are getting read from the versions.json (including PacketMapping)
• Enchanted DNS support (SRV Resolve): 04ab1b52
• Velocity: Velocity is not an attribute of an entity, handling happens in VelocityHandler now
• serverWrapper Util: Tell me your wanted Minecraft server version, and I'll start it for you :)
• enum refactoring: Use ordinal and values() function

ToDo:

• Everything in docs/snapSupportToDo.txt (unimportant)
• Entity Meta data (they are complete broken)
• 1.16.2 support (20w30a works)

Fixes #5 (closed) #2 (closed)