* Fix PQL distinct in dax
When issuing a PQL Distinct() call (or any other call with a "index=" arg),
this commit will attempt to convert the value in the index arg with a
TableKeyer.
* Apply change to call.Children as well
* Add some PQL Distinct (join) test coverage
(cherry picked from commit 4e8fe488de)
this commit changes the way the plan is retrieved; implements Stringer on types.PlanExpression in preparation for HAVING support; removes last vestiges internal float64 arithmetic; implements a filter on PlanOpFilter; fixes various bugs in the PlanOptimizer when rewriting qualified references
* fixed selects with unqualified identifiers
* handle bad and non-existent query param inputs more appropriately
* added test coverage for PlanExpression Stringer
Co-authored-by: Matthew Jaffee <jaffee@pilosa.com>
(cherry picked from commit 5f662d2bce)
