Adds model extensions prototyped in the EU CyberKit4SME project:
authorization code flows in the OIDC/OAuth-style authentication/authorization service model
key vaults controlling access to data, extending the OIDC/OAuth-style model used for service access control
data fields as elements of data schema allowing distinct impact levels for sensitive elements, and selective cryptographic protection using keys from a key vault
Adds model extensions prototyped in the EU CyberKit4SME project:
Closes #40, #42, #59, #85, #86.