Converts an ID to the signed long integer representation used internally
Request:requestType is longConvertid is the numerical ID, in decimal form but equivalent to an 8-byte unsigned integer as produced by SHA-256 hashing
Response:
(S) stringID is the numerical ID
(S) longID is the signed long integer (8-bytes) representation of the ID used internally, returned as a string
(N) requestProcessingTime is the API request processing time (in millisec)
Note: Java does not support unsigned integers, so any unsigned ID (such as a block ID) visible in the BRS client is represented internally as a signed integer.