Replace "revoked" by "verified" in credential status verification

There are some JSON-LD libraries that work with credential-status which, instead of an object with a `revoked` property, adopted an object with a `verified` property, similar to the result of a VC verification. It allows developers:
- to issue credentials that can also be suspended, instead of only a revoked.
- to issue credentials in an invalid state and later turned valid.
- to more easily switch to Veramo without writing adapters for them.