IssuerSignedItem
A data structure representing IssuerSignedItem in ISO/IEC 18013-5:2021.
This is stored as a DataItem to preserve the order since the result of calculateDigest depends on the exact bytes generated by the issuer. Since ISO/IEC 18013-5:2021 Clause 8.1 puts requirements on integers and lengths, the only variable thing is map order meaning it's sufficient to use a DataItem instead of the exact bytes from the issuer.
Individual components can be retrieved using the digestId, random, dataElementIdentifier, and dataElementValue properties.