V22.1.0 + Complete refactor

[jmarrec]

Complete refactor of the C++ code to eliminate global state, use constexpr, avoid gotos

This builds upon #91, but I didn't want to put it there because this is untested yet.

[antoine-galataud]

@jmarrec thanks for the refactoring, I have to test that.

[jmarrec]

https://github.com/jmarrec/EnergyPlus/releases/tag/v22.1.0-rl-testbed-refactor

Diff: https://github.com/jmarrec/EnergyPlus/compare/v22.1.0-rl-testbed...jmarrec:v22.1.0-rl-testbed-refactor?expand=1

[jmarrec]

FYI in 536db89 I made some extra refactoring, which will correspond to this new release: https://github.com/jmarrec/EnergyPlus/releases/tag/v22.1.0-rl-testbed-refactor-extra

diff : https://github.com/jmarrec/EnergyPlus/compare/v22.1.0-rl-testbed-refactor...jmarrec:v22.1.0-rl-testbed-refactor-extra?expand=1

In that one:

• I cleaned up the API (correct types for params, return types)
• set up error codes from Erl in case something went wrong
• and added ExtCtrlObs/ExtCtrlAct to the C and Python API
  • The usefulness of that part is quite limited since you can already achieve everything you're doing without doing any patching via this API with the current actuators / sensors. That would require moving to Python (or... C... but who would) instead of using Erl (EMS). So if you do move to a Python EMS code instead of Erl, then the ExtCtrl stuff becomes kinda pointless. But hey, why not right?

This is again untested, so perhaps you'll want to revert 536db89.

[antoine-galataud]

tested the main loop and it works fine. I didn't test new error codes handling and integration in C/Python API, but shouldn't be a problem to merge as is and see if it's functional and useful later.