Gproano/complete siop validation

[gproanomsft]

Problem: Siop Token Validation was incomplete

Solution: Validate the did, sub_jwk and sub claims in a siop id token

Validation: Fix existing unit tests and add new ones to test validation

Type of change:

• [x] Feature work
• [x] Bug fix
• [ ] Documentation
• [ ] Engineering change
• [ ] Test
• [ ] Logging/Telemetry

Risk:

• [x] High – Errors could cause MAJOR regression of many scenarios. (Example: new large features or high level infrastructure changes)
• [ ] Medium – Errors could cause regression of 1 or more scenarios. (Example: somewhat complex bug fixes, small new features)
• [ ] Small – No issues are expected. (Example: Very small bug fixes, string changes, or configuration settings changes)