Add missing test cases for CI flow

[giovanni-riela]

Motivation and Context

The primary goal of this PR is to bridge the gap in test coverage for the issuance flow, specifically focusing on metadata validation, credential offer structure, and the security of wallet attestations. By adding these conformance tests, we ensure that the wallet implementation correctly handles both happy-path scenarios and various failure modes required by the technical specifications.

Key Changes:

• Expanded Conformance Coverage (Issuance):
  • Metadata & Trust Validation: Added tests (CI_004, CI_005) to verify public key inclusion in Entity Configuration and Subordinate Statements and ensure the presence of Trust Marks.
  • Credential Offer Compliance: Implemented structure and parameter validation for Credential Offer URIs (CI_010, CI_012, CI_013), supporting both embedded and fetched offers.
  • Wallet Attestation Security: Introduced critical security checks (CI_031, CI_032, CI_033) for Pushed Authorization Requests (PAR), validating the rejection of tampered, expired, or improperly signed attestations.
  • Credential Integrity: Added CI_014 to verify the proper compilation of issued credentials using DCQL queries.