HPCC-10142 Support queryLogicalFilename on hthor

Build superfile name structure to enable mapping of subfiles into supers

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
I tested this change with my issue10142.ecl which is generates logical files and uses two multipart logical files (generated by the setup on multislave thor),  assigns all those files into a superfile then adds this superfile to a super-superfile.