Test RevocationList2020Status in VC API

[clehner]

Add RevocationList2020Status to credentialStatusesSupported in the local VC (HTTP) API Test Suite config, to cause Revocation List 2020 functionality to be tested. This should have been added before, but was forgotten. However, adding it now will probably cause test failure, as the test revocation list credential and its dependent credential statuses have been broken in the renaming of vc-http-api to vc-api: w3c-ccg/vc-api#236

The test suite itself could also be similarly updated for Spruce's demo instance: https://github.com/w3c-ccg/vc-api-test-suite/blob/a74c63d2d015efcb1c5d22a5d283536026faf5ec/packages/vc-http-api-test-server/config/Spruce.js#L18

Edit: actually, this change would cause issuer tests to run as well, which DIDKit doesn't currently support: the credentialStatus issuance option is supposed to result in a credentialStatus object added to the resulting verifiable credential:
https://github.com/w3c-ccg/vc-api-test-suite/blob/a74c63d2d015efcb1c5d22a5d283536026faf5ec/packages/vc-http-api-test-server/__tests__/issueCredential.spec.js#L126-L166

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[sbihel]

Closing old PRs