Merged the groundwater approval code and refactored to keep all of the info needed to render tooltips, legend data and groundwater visit circles in selectors/discrete-data.js

Fixed conversion of celsius 0 to Fahrenheit.

Wdfn 501

Made the compare toggle disabled when custom date range or period. Fixed some issues that occurred while switching time periods that cause the primary parameter to be null. Also eliminated an needed service calls when that data is not requested or not available.

Wdfn 501 - Cleaned up the code, all tests run, tests were added for new functions

Iow 867 use colors for approved provisional groundwater

Made the fetching functions a little less brittle and updated some of the hydrograph rendering tests.

Iow 866 add approvals to groundwater levels table