Add OAuth2 Token Revocation Endpoint for Applications

This PR adds a new endpoint to revoke all OAuth2 tokens for a specific application for the authenticated user. The implementation:

• Creates a newPOST /oauth2-provider/apps/{app}/revoke endpoint that revokes all tokens and authorization codes for a specific OAuth2 application
• Handles both authorization code flow tokens and client credentials flow tokens
• Updates the frontend to use this new endpoint instead of the previous token revocation method
• Adds comprehensive tests to verify token revocation works correctly for different scenarios
• Implements tracking of client secret usage by updating theLastUsedAt timestamp when a secret is used for authentication

The new endpoint provides a more efficient way to revoke all tokens for an application in a single request, improving security by allowing users to quickly revoke access when needed.