Forecast Options Tab - PN Refinements

[tjrocha]

• Allow users to drag-and-drop top-level predictor names from the All Available Predictors tree into the PredictorPool container under the adjacent Equation Pools tree. Code should filter through the subsetted predictors and only add predictors that are in the past relative to the equation. (Ex: dropping SNOTEL site X into the January-01st equation should only add subsetted predictors that come before January and/or aggregated from Oct-01 to Dec-31)
• Catch error when Apply Options is pressed when the dataset dictionary is empty

[tjrocha]

!@#$%! modifying the monthLookup function broke the Apply Options in the Forecast Options tab! Fix it!

[tjrocha]

This is why you need to work on #2!

[tjrocha]

Tester requests that only the EOM chunked predictor be added to the equation when dropping a station-node for monthly forecasts. Need to refine the implementation to also resolve this for mid-month forecasts such that only chunked predictors that go to the 14th will be added...

An alternative is to make it so the code does not generate predictor chunks that end in the 14th day if the forecasting frequency is set to monthly (no mid-month forecasts).