[FTS] Testing query_string combinations reveals differences in query_string queries of FTS and ES

Build
5.0.0-1755

Testcase (not merged yet)
./testrunner.py -i INI_FILE.ini -t fts.stable_topology_fts.StableTopFTS.test_query_string_combinations,items=10000,compare_es=True,dataset=wiki,skip-cleanup=True

A test of 216 combinations of should, must, must_not clauses to discover differences in query_string queries of Couchbase FTS and ES.

Result
AssertionError: 99 out of 216 queries failed! - [1, 4, 6, 20, 21, 23, 32, 33, 35, 110, 111, 113, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 128, 129, 131, 133, 134, 135, 136, 137, 138, 140, 141, 143, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 182, 183, 185, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 200, 201, 203, 205, 206, 207, 208, 209, 210, 212, 213, 215]

Complete test log here - https://gist.github.com/arunapiravi/051162b8b6907cede508ec63e6c6e486