Relax Data Explorer query on string-based fields

[isangil]

Case: We configure text-based variable filters for the data explorer. When using such query pages, the
expectation is that we see results on partial matches.

Example: We can query on a "Location Name". We do not know the exact names, so we enter
"Lake". Currently, it yields no results, as the table column "location Name", has values "Lake Bonney", "Lake Hoare", etc. What we ought to do is relax the query, from exact match, to use the operator "LIKE".