ENG-4086 Use index scan on JSON FIELD LIKE prefix.
In plannertester, add indexed json suite (including indexed LIKE), refresh (recently?) improved voltcache baseline plans.
Merge branch 'master' into ENG-4086-json-like
Fix overreach in JSON LIKE optimization -- would abuse index for wrong answers.
Re-enable function tests.
Merge pull request #382 from VoltDB/ENG-4086-json-like

Eng 4086 json like