Remove "Compatibility with Key Management Methods (Issuer)" from Credential-Format

[cre8]

In the specification we have the field Compatibility with Key Management Methods (Issuer) to set the key management method for the issuer.

In my opinion this is part of the Credential Profile and not of the format. It could lead to inconsistency if a profile says "i use did:jwk" as the key for the issuer, but it is not listed in the used credential format (in case of W3C VC all did are usable, so the list would be very long and needs updates all the time).