2.0.0-beta.1+1.18: [2.0.0-beta.1] Client side models and lots of improvements

- Added client side custom model for `player_head` style
- Added `client_model` grave style for more traditional look for modpacks
- Added death compass (enabled by default)
- Added ability to view content of grave remotely with /graves command
- Added `universal_graves:visual_grave` block which can be used for decorative purposes, it can be obrained only with commands for now
- Changed way graves are stored to allow more flexibility
- Changed how quick pickup works, now it tries to put items in correct slots (including modded like trinkets)
- Changed from usage of real time to game time (you can toggle it to old behaviour in the config)
- Changed `player_head` style to turn into skull if grave is unlocked (can be disabled)
- You can now disable holograms for players with mod on client side (for usage with `client_model`)