Improved handling of errors within test framework
Improvements
- Godot exits with error code 1 if test scene runner tries and fails to run
- SceneScout detects and handles (more) unrecoverable errors
- SceneScout is used when running individual test scenes (without test scene runner)
- SceneScout tries to work around wrong number of test runners within test scenes (either 0, or >1)
Fixes
- Minor .gitlab-ci.yml cleanup
- Add missing new/renamed resources to export config
Tests
- Test scene without any test runner