Surveyor Map Framework

Changes:

• redo packet definitions - be sure to update server and client at the same time.
• adds terrain sync on world load.
  • this means map sharing is forced on globally for now, synchronized on each connection.
  • proper map sharing (and structure / landmark visibility) still to come.
• fix a bug where surveyor would save data to the client folder while in singleplayer.

Changelog: https://github.com/sisby-folk/surveyor/releases/tag/v0.1.0-alpha.4