Updating generator and engine following 🎄 christmas refactoring

• Updated generator to resepect project structure set in 🎄 christmas refactoring
• Made internal include paths relative to src or gen. See https://gitlab.eclipse.org/eclipse/simopenpass/openscenario1_engine/-/merge_requests/85#note_1057171)
• Updated all copyrights
• engine/gen is now a clean check-in of generated files after 🎄:
  • Moved implemantation of UserDefinedValueCondition to src
  • Moved implemantation of VisibilityAction to src
  • Generation of LateralDistanceAction cannot handle annotation "IsSetDynamicConstrains". The corresponding files have been updated manually and then moved to src. The generator will not generate these files anymore (unless forced). See https://gitlab.eclipse.org/eclipse/simopenpass/openscenario1_engine/-/issues/17