decodeAsn1VarBigInt
Decodes an ASN.1 unsigned varint to a Asn1Integer, copying all bytes from the source into a ByteArray.
Return
the decoded Asn1Integer and the underlying varint-encoded bytes as ByteArray
Parameters
limit
maximum bytes to consume, or null for an already bounded source
Throws
if the varint is unterminated at source exhaustion, or exceeds limit