Add support for verifiable credentials

[ahmed-arb]

Verifiable credentials are supported by the credentials service. The following presentation and documentation have a more in-depth context:
https://www.youtube.com/watch?v=HQ7e0OQQEBE
https://docs.openedx.org/projects/edx-credentials/en/latest/sharing/verifiable_credentials/overview.html

Additionally, this plugin by racoongang sets up the required configurations:
https://github.com/raccoongang/tutor-contrib-badges

[ahmed-arb]

Apart from following the steps in the official docs, we need to add an entry in the "Credentials api configs" table in lms admin and check the "Enable Learner Issuance" flag.

[ahmed-arb]

Created a PR to add Wikimedia's testing issuer.
digitalcredentials/sandbox-registry#26

[ahmed-arb]

Discussion post for bugs credentials and LCW bug: https://discuss.openedx.org/t/verifiable-credentials-qr-code-scan-issue-stuck-at-credential-storage-step/18349/6

[ahmed-arb]

Status update on enabling Verifiable Credentials on production.

Done

• Opened a PR on tutor-contrib-wikilearn to apply the LC Wallet compatibility fixes to the Credentials image. It backports openedx/credentials Adding ability to give an attribute callback for CAS openedx/openedx-platform#2948, Ensure account creation succeeds before creating comments service user openedx/openedx-platform#2957 and Instructor dash changes for DOC-231, resequencing for DOC-230 openedx/openedx-platform#2976 via a credentials-dockerfile-post-git-checkout patch, since the release/teak.3 base predates them: Apply LCW compatibility fixes to the Credentials image tutor-contrib-wikilearn#53
• Generated the production issuer (DID + private key) on the prod Credentials service and added it to the Issuance Configuration in the credentials admin. The status list endpoint is live, publicly reachable over HTTPS, and signing correctly (https://credentials.learn.wiki/verifiable_credentials/api/v1/status-list/2021/v1/did:key:z6MkpVHVNkhQTQJnBGNjHnxPH7QictB7Mf6mkp8Ghv28b1bN/).
• Shared the issuer registry registration details and options with the client (DCC membership for the community registry vs the Credential Engine registry).

Waiting on

• Access to the deployment configuration repo to make the credentials and discovery related changes to the deploy workflow (build and push the Credentials image so the patch above ships, etc.). Prepared the change as a patch and shared it with DevOps in the meantime.

Remaining

• Set up the cronjob to sync certificate data from LMS -> Discovery -> Credentials service.
• Run the deployment.
• Test the end-to-end VC issuance flow in the LC Wallet.

[ahmed-arb]

Created this registery PR for prod:
digitalcredentials/community-registry#21