Clarify how EnvelopedVerifiableCredential and JWTs can be verified

[robdefeo]

As per https://www.w3.org/TR/vc-jose-cose/#securing-vps-with-jose I can see that the request is valid for /presentations/verify

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://www.w3.org/ns/credentials/examples/v2"
  ],
  "type": "VerifiablePresentation",
  "verifiableCredential": [{
    "@context": ["https://www.w3.org/ns/credentials/v2"],
    "type": ["EnvelopedVerifiableCredential"],
    "id": "data:application/vc-ld+jwt,eyJraWQiOiJFeEhrQk1XOWZtYmt2VjI2Nm1ScHVQMnNVWV9OX0VXSU4xbGFwVXpPOHJvIiwiYWxnIjoiRVMzODQifQ.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.d2k4O3FytQJf83kLh-HsXuPvh6yeOlhJELVo5TF71gu7elslQyOf2ZItAXrtbXF4Kz9WivNdztOayz4VUQ0Mwa8yCDZkP9B2pH-9S_tcAFxeoeJ6Z4XnFuL_DOfkR1fP"
  }]
}

However for credentials/verify the format is a JWT which does not appear to be acceptable according to verifier.yml. https://www.w3.org/TR/vc-jose-cose/#securing-with-jose

application/vc-ld+jwt
eyJraWQiOiJFeEhrQk1XOWZtYmt2VjI2Nm1ScHVQMnNVWV9OX0VXSU4xbGFwVXpPOHJvIiwiYWxnIjoiRVMyNTYifQ .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 .CDmIvQ4nG6iZxBNX86-3BR38KFB9JP5wKO7kiGohXG41gnfxD8k1eD-a5PWskMrGJcDipfyk-TRGjaxMP3kasQ

example secured credential, which has no envelope, however it would be valuable to be able verify

Also there are use cases when it would be helpful to verify application/vc-ld+jwt and application/vp-ld+jwt directly, can the spec be adjusted to accept string also

[jrhender]

I think this issue relates to issue #357 where the POST /credentials/issue and POST /presentations endpoints were modified to allow return of an EnvelopedVerifiableCredential or an EnvelopedVerifiablePresentation respectively.

However #357 didn't change the request schemas for the POST /credentials/verify and POST /presentations/verify, which I think should also be done. My initial thought is that adding EnvelopedVerifiableCredential and EnvelopedVerifiablePresentation as possible schemas for the verify endpoint request schema would be a good step.