refactor(core): Distinguish Model Manager on CTO or AST, revise addModel operations

[jeromesimeon]

Signed-off-by: Jerome Simeon [email protected]

Changes

• Further clean up CTO dependent code
  • Remove parser dependency in MetaModel module in core
  • Distinguish addModelFile (over AST) and addCTOfile (over CTO) in the model manager
  • concerto-core now depends only on AST versions rather than CTO versions of the two built in models: namespace concerto and namespace concerto.metamodel
• New BaseModelManager is Concerto AST-only dependent while legacy ModelManager supports full CTO syntax. The two model managers only differ in how they process input files. Only the legacy ModelManager depends on the CTO parser.

Flags

• Further work would still be needed to be able to fully reverse the dependency from core to cto:
  • Move legacy ModelManager into @concerto-cto and reverse the dependency from concerto-core to concerto-to
  • Adjust the ModelLoader class accordingly or move it
  • Update all the tests that still depend on CTO syntax in concerto-core to rely on the AST instead -- big change but conceptually simple