SES-1803 : Add \f and \b to NTriplesUtil.unescapeString
SES-1803 : Replace SPARQLUtil.decodeString with
NTriplesUtil.unescapeString
SES-1720 : Deprecate Literal methods in QueryEvaluationUtil that will
simply not work with RDF-1.1 due to it not recognising the concept of
Plain Literals or Simple Literals.
SES-1803 : Reuse NTriplesUtil in SPARQLOperation
SES-1803 : Datatype will not be null, so remove check on it
SES-1803 : Remove unnecessary cases since datatype will never be null
anymore