Reasoner-pydantic

Fixes:
* MetaKnowledgeGraph `nodes` and `edges` are required, but `edges` may be empty

Bug fixes:
* Convert `negated` to `not` in `.dict()` even without `by_alias=True` - this is necessary for FastAPI to generate `Responses`
* Point `Query`, etc. to the correct Workflow
* Make `Operation` ids strings
* Remove standards.ncats.io `$refs` - these are not necessary for _equivalence_ of the schema with TRAPI, and were causing issues in Swagger UI

Bug fixes:
* Convert `negated` to `not` in `.dict()` even without `by_alias=True` - this is necessary for FastAPI to generate Responses

Fixes the missing `Attribute.description`.