doDecode
Decodes an Asn1Primitive into a specific Asn1String subtype based on its tag.
For cases where an implicit tag is required, see the helper extension methods like decodeToUtf8String, decodeToPrintableString, etc., which allow specifying an optional tag override.
Return
the corresponding Asn1String subtype
Parameters
src
the ASN.1 primitive to decode
Throws
if decoding fails or the tag is unsupported