[Feature]: Merge @retoph refactored codebase

[PBechon]

@rettoph have completely re-written kerbal simpit, mainly for breaking the core simpit protocol into its own .net standard library.
This refactoring have been used by himself but not tested by a big number of players. It should be easier to start from here for a new implementation (for instance KSA ...).

Core Simpit: - Includes Unity hooks if needed, but can just as easily be used in any c# app
KSP Simpit: - Integrates KSP specific logic and messages

Arduino Core Simpit
Arduino KSP Simpit

No decision has been made to support this refactoring of not, this issue is created to discuss and keep track of this refactoring.

[rettoph]

If this refactor is the future of the project then quite a few things need to be considered and implemented first

• Documentation needs to be nearly entirely rewritten
• Example snippets must be updated
• KSP2 support needs to be re-implemented
  • Does it, though?
  • This should be less complex than it sounds
• A new repo needs to be created to hold the core code vs ksp code
  • Same for the Arduino code
• Lots and lots of stress testing

In its present state this refactor is good enough for my personal use and I have no intentions of updating the items listed above unless the community decides to move forward with this refactor in an official capacity. In that event I will gladly jump back in and help contribute wherever possible.