Architecting TM support

[FadySalama]

1. General:

   • [x] We do JSON, JSON-LD, normal TM validation and probably additional check (need to restructure core package)
   • [x] New assertion validation for TMs

2. Assertions Package:

   • [x] Add 2 assertion folders and 2 list.json for TMs and TDs

3. CLI consideration

   • [x] Add options for validating TM or TD
   • [ ] Allow the user to specify additional schemas for validation?

4. Frontend (low priority)

   • [x] Dynamically detect TD or TM etc...