doDecode
Decodes an Asn1Primitive into a specific Asn1String subtype based on its tag.
This generic decoder requires the universal ASN.1 string tag to stay visible. If the value was implicitly tagged, decode it through a concrete subtype decoder such as decodeToUtf8String, decodeToPrintableString, or another specific string decoder.
Return
the corresponding Asn1String subtype
Parameters
src
the ASN.1 primitive to decode
Throws
if decoding fails or the tag is unsupported