feat: add support for OpenID4VP

[nanderstabel]

Description of change

See title

Links to any relevant issues

#22

How the change has been tested

Added and improved aggregate tests.

How to manually test this change:

1. Simply run UniCore (cargo run)
2. Run UniMe on a physical device using this branch: chore: bump oid4vc dependencies identity-wallet#197
3. Use the Postman collection to send both the /v1/credentials request and the /v1/offers request.
4. Render the encoded string that is returned as a QR code.
5. Scan the QR code with UniMe and accept the offer
6. Use the Postman collection to send the v1/authorization_request request.
7. Render the encoded string that is returned as a QR code.
8. Scan the QR code and accept the Authorization Request
9. UniCore will successfully verify UniMe's Authorization Response

Definition of Done checklist

Add an x to the boxes that are relevant to your changes.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[github-actions]

🎉 This PR is included in version 1.0.0-beta.1 🎉

The release is available on GitHub release

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[github-actions]

🎉 This PR is included in version 1.0.0-alpha.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀