Draft 14

[babisRoutis]

Closes #309
Closes #295
Closes #294
Closes #316

[babisRoutis]

@vafeini Added in scope #316

We need to
a) Re-work the response of the deferred endpoint, since now a transaction_id corresponds to one or more credentials
b) Re-work IssuedCredential. The IssuedCredential.Deferred must be removed
c) Re-work on the SubmissionOutcome. We need to add Sumbission.SuccessDeferred

[babisRoutis]

The following change was necessary:

Submission outcome has now three possible states: Success (or Issued), Deferred, Failed.

sealed interface SubmissionOutcome : java.io.Serializable {

    /**
     * State that denotes the successful submission of an issuance request
     * @param credentials The outcome of the issuance request.
     * If the issuance request was a batch request, it will contain the results of each issuance request.
     * If it was a single issuance request list will contain only one result.
     */
    data class Success(val credentials: List<IssuedCredential>) : SubmissionOutcome

    /**
     * Credential could not be issued immediately. An identifier is returned from server to be used later on
     * to request the credential from issuer's Deferred Credential Endpoint.
     *
     * @param transactionId  A string identifying a Deferred Issuance transaction.
     */
    data class Deferred(val transactionId: TransactionId) : SubmissionOutcome

    /**
     * State that denotes that the credential issuance request has failed
     *
     * @param error The error that caused the failure of the request
     */
    data class Failed(val error: CredentialIssuanceError) : SubmissionOutcome
}