/**
* Initial request that checks if a matching, not expired, sort result record exists, creates a new record if not, returns sortResultId
* @param {string} event.searchDataId - {searchType}_{filterId}_{keyPropertiesHash}_{requiredDataHash}
* @param {Object[]} event.sortFields - sort fields
* @param {string} [event.sortFields[].dataField] - name of the field being sorted, not used if randomSeed is set
* @param {string} [event.sortFields[].randomSeed] - set when wanting random order only
*
* @returns {string} sortResultId
*/