Create central place for test /mock credentials

[alexfigtree]

...to put in docs WIKI and vc-test-fixtures (to be renamed) repo

Should Include:

• add mock creds for testing renderMethod
• Also include QR codes for each credential for wallet testing
• Issue Example Credential with CBOR-LD QR Code #10 in docs
• VC 2.0 credential should be added*
• Baked badges credentials (use credlys, but discourage use?)
• Others?
• Put all inside vc-test-fixtures (rename to sample-vcs)
• Remove add mock cred button LCW
• Also take into account mock credential issues from LCW as well:
  Add 2.0 cred to Mock Creds (for use and testing) openwallet-foundation-labs/learner-credential-wallet#643
  Remove Credentials section from dev menu on LCW openwallet-foundation-labs/learner-credential-wallet#571

*From openwallet-foundation-labs/learner-credential-wallet#643: V.2 creds should be added here: https://github.com/digitalcredentials/vc-test-fixtures/tree/main/verifiableCredentials/v2