Hopefully renaming Content to CrossClass will un-ruin the hotfix.

Added empty item XML to hopefully make the game realize this is a mod it should download and install like a normal mod

- Added save / load system for cross class values.
- Removed from singleplayer games (will politely error and not patch).
- Save files can be found under `steamapps/common/Barotrauma/LocalMods/.modstore/CrossClass.CrossClass/{campaign_name}/character_data.json`

Removed a bunch of LuaCsLogger calls used for debugging