update QP max results limitations in a few ways:

* set the absolute limit up to just over 1m rows, which is the max Excel allows.
* allow query execution callers to specify their own :max-results and :max-results-bare-rows values so that we can contextually constrain the result sizes.  this allows us to easily have the api allow 10k results, a pulse allow 500 results, and a CSV download to allow 1m results.