fix: change url to uri

[nanderstabel]

Description of change

As title

Links to any relevant issues

• fix: use "uri" instead of "url" when reading display properties identity-wallet#300

How the change has been tested

• Tested using the Postman Collection (checking the response from the oid4vci/openid-credential-issuer Request
• Tested manually with UniMe

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
• I have successfully tested this change in a docker environment