✨ Update engine to OpenSCENARIO 1.2.0

• Uses OpenScenarioLib v1.3.1
• Adds patch for OpenScenarioLib to generate code model for generator
• Updated documentation (e.g. all links use correct URLs)
• Updated generator templates
  • namespace v1_1 -> v1_2
  • Logger instead of std::cout
  • Code improvements introduced through clang-tidy
  • Minor fixes
• Updated generated and existing (incl. tests)
• Make all tests run

Closes #19 (closed) #31 (closed)