sfmlv3 migration PR

[dogunbound]

Still a WIP. Second commit is to get the libraries to compile.

Miscellaneous TODO list:

1. Get the examples to compile again

Missing v3 feature list:

1. sf::WindowBase::handleEvents
2. Fix Style enum to match SFML's enum
3. sf::Angle
4. Ensure sf::Vector2and3 has the same functions as base SFML
5. Evaluate the completion of ALL features. I have yet run a double check on every single feature and ensure we aren't missing something we intend to keep
6. https://www.sfml-dev.org/tutorials/3.0/getting-started/migrate/#deprecated-apis Need to run through this list
7. https://www.sfml-dev.org/tutorials/3.0/getting-started/migrate/#anti-aliasing-renamed Need to run through this too
8. I personally haven't dove into SFML audio all that much, so there may be a few things I'm missing. Need to investigate

Possibly more other things missed. lmk if you find other stuff

[crumblingstatue]

Thank you for the monumental effort!
I can't promise I'll do a thorough review soon, but I'll take a peek tomorrow.

[dogunbound]

Thank you for the monumental effort! I can't promise I'll do a thorough review soon, but I'll take a peek tomorrow.

Still got some ways to go, but wanted to throw it up to show the progress I have made so far. No rush for a "real review" as I said, still got some ways to go :)

[dogunbound]

Added a TODO.md for the missing features.

[crumblingstatue]

Hmm, I suppose there is no real reason to hold this back anymore. It will still have time to cook on the main branch before release.