- 4.3 release work
    - update docs
        - [ ] spine-godot
        - [ ] spine-ue (setToSetupXXX nodes have been renamed to follow new nomenclature)
        - [x] spine-c
        - [x] spine-cpp
        - [x] spine-flutter
        - [x] spine-ios
        - [x] spine-sdl
        - [x] spine-sfml
        - [x] spine-glfw

- Port C++ SkeletonRenderer and RenderCommands to all runtimes
    - Will be used to snapshottesting via HeadlessTest, see also tests/
    - Can go into main package in all core runtimes, except for spine-libgdx, where it must go next to SkeletonSerializer in spine-libgdx-tests
- Generate Godot wrappers from C++ types and/or spine-c generate() (unlike dart-writer.ts)?
- headless-test improvements
    - should take cli args for ad-hoc testing
    - if none are given, should execute a set of (regression) tests and output individual test snapshots one after the other as jsonl
    - All headless tests must have the same test suite
    - test runner must know how to deal with this mode
- Add serializer generator for C#
- Add serializer generator for TypeScript
- spine-c/codegen type extractor should also report typedefs like typedef long long PropertyId; so primitive type to some name, and we need to handle that in the codegen