Pediatric investigational plan number needs to be addressed. [API]

[BSnoeijerCD]

Pediatric investigational plan number needs to be addressed. It is more a reference than an identifier. See EMA template https://www.ema.europa.eu/en/documents/template-form/paediatric-investigation-plan-pip-key-elements-guidance_en.pdf See feature ticket #420

[ASL-rmarshall]

@dih-cdisc I've updated the API specs in the release-3-6-0 branch in both usdm_api and DDF-RA to:

• Add the Identifier class - copied from StudyIdentifier and then:
  • renamed studyIdentifier to text
  • renamed identifierScope to scope
  • updated instanceType
• Changed the StudyIdentifier class to:
  • Inherit from Identifier instead of the base model
  • Remove specifications for studyIdentifier and identifierScope
• Added ReferenceIdentifier class as a copy of the updated StudyIdentifier class and
  • Added type as Code
  • Updated instanceType
• Updated StudyVersion to:
  • Add referenceIdentifiers as a copy of studyIdentifiers, updating name and class
  • Make studyIdentifiers required (removed = [])

Let me know if I missed anything...