Update test suite and directions for those implementers who support VC JOSE COSE

[brentzundel]

The directions for interacting with this test suite are not clear about how to demonstrate interop with Bitstring Status List for implementers who do not use Data Integrity for securing VCs. It also seems that VC API is a required technology.

My company has an implementation of Bitstring Status List signed using JWTs. Does the test suite support this? If not, can if be updated?

Additionally, pointing to the VC API as a mechanism for interacting with the test suite is not helpful for companies such as mine which are not planning to implement it. I understand that an API endpoint should be made available. Can the directions be updated to simply describe the minimal necessary endpoint? Is there perhaps an OpenAPI spec one could be referred to?