feat: add azp claim

[roee-hersh]

Description

Add support for the azp (Authorized Party) claim in JWT token client ID extraction to improve compatibility with OpenID Connect standard implementations.

Problem: The current JWT verifier only checks client_id and sub claims when extracting the client identifier from JWT tokens. However, many identity providers (including Keycloak, Auth0, and other enterprise OIDC implementations) use the azp claim to represent the client application ID, as defined in the OpenID Connect Core 1.0 specification.

Solution: Extended the client ID extraction fallback chain to include the azp claim:

# Before
client_id = claims.get("client_id") or claims.get("sub") or "unknown"

# After  
client_id = claims.get("client_id") or claims.get("azp") or claims.get("sub") or "unknown"

This change maintains full backwards compatibility while supporting standard OIDC implementations that rely on the azp claim for client identification.

Contributors Checklist

• My change closes Add support for azp claim in JWT client ID extraction #1943
• I have followed the repository's development workflow
• I have tested my changes manually and by adding relevant tests
• I have performed all required documentation updates

Review Checklist

• I have self-reviewed my changes
• My Pull Request is ready for review

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Note: You'll need to create an issue first describing this enhancement before submitting the PR, and then update the issue number in the checklist above.

[jlowin]

That makes sense to me, can you please add a unit test to confirm its loaded as expected?