ELM v3.2 - Alignment with VC 1.1

[shikhat-karkee-cognizone]

This PR contains VC 1.1. alignment updates. It mainly covers:

• update of ontology.
  • addition of Proof, TermsOfUse and CredentialStatus class
  • import Security Vocabulary's ontology
  • updated version & modified date metadata
• update of EDC AP SHACL:
  • update of proof property prefix from https://www.w3.org/2018/credentials# (cred) to https://w3id.org/security# (sec)
  • addition of shapes for new Proof, TermsOfUse and CredentialStatus classes.
  • update of range for proof, termsOfUse and credentialStatus property of European Digital Credential class.
  • update of mandatory URI usage for credentialSchema and credentialStatus property of European Digital Credential class.
  • update of version and modified date metadata
• update of EDC JSON-LD Context file:
  • addition of Proof, TermsOfUse and CredentialStatus terms.
• update of respective EDC AP SHACL and Ontology RDF/XML files
• update of EDC SHACL AP and Ontology documentation
• update of credential sample files