Issuance request/response updates

[dtsiflit]

The following updates have been introduced regarding issuance request payload:

• Remove proof attribute from issuance request. Its equivalent is a proofs array with one proof included
• Update credential_response_encryption as specified here

The following updates have been introduced regarding issuance response:

• If issuance is deferred, response contains interval along with the transaction_id
• If credential request's credential_response_encryption included a zip algorithm and issuer supports compression before encryption, response must be decomporessed after decryption.
• Align error codes mentioned here