Add CRTDL validate endpoint

[juliangruendner]

Add CRTDL validate endpoint

base ideas:

• 200 OK if validation fails
• 400 if CRTDL invalid (e.g. not matching schema or not a CRTDL at all)

things to validate:

cohortDefinition:
see: #688

dataExtraction:

• each groupReference can be resolved in ontology dse_profiles
• attributes of DSE features (attributeGroups) (fields) not in ontology profile for feature
• filter not valid (e.g. codes not available in value set anymore) -> code available in val set, filter in general alllowed (e.g. date, code) for attributeGroup
  - valid patient profile (note that the UI and backend always accepts exactly one patient profile) - if different patient profile in CRTDL throw error accordingly
• ensure linkedGroup exists for each attribute of type "reference" in dse profile
• if linkedGroup exists ensure that ids it links to exist in the CRTDL

Example CRTDL complex:

example-complex.json

[michael-82]

valid patient profile (note that the UI and backend always accepts exactly one patient profile) - if different patient profile in CRTDL throw error accordingly

This is currently not really possible to validate. We need to rethink this. It will be removed from this issue.