Feature branch for v2.0.0

[TisRyno]

This update addresses a lot of bugs and includes a major refactor of the core plugin.

• [x] moved GUI components into their own classes to remove them from core logic
• [x] fix up code style and use newer types
• [x] fix sprint speed desync and mod conflict issues by using opcodes
• [x] fix battery life GUI not being synced with drain
• [x] fix loot value not always applying by using opcodes
• [x] fix jump height desync issues
• [x] remove Oxygen skill (rarely ever used by players and would rather not have to maintain it)
• [x] add new config parameter to carry over skills after being fired

Still planned:

• [ ] review hand slots issues #29
• [ ] check for strength bugs when an item weighs nothing #32
• [ ] fix HP regen issues with server-side damage control #33
• [ ] rebuild the XP.cs file to not be so large and unworkable
• [ ] move all skill patches into patch files