Include all map polygons in feature/station criteria

[jameshiebert]

Related to #43, the current PCDS portal allows for multiple polygons to be drawn on the map and included in the station filter criteria.

Presently, the current UI allows the user to draw multiple polygons, but only uses the first one in the filter criteria. This should be amended.

[jameshiebert]

Another consequence of this issue is that, the spatial selection that gets submitted to the PCDS portal does not comply with the PCDS portal's current expectation. The PCDS portal expects a MULTIPOLYGON and does not match a single POLYGON. So until this issues is fixed, the station-data-portal cannot do any spatial filtering for data requests.

[corviday]

Hopefully updating this function is all that will be required.

[rod-glover]

I believe recent changes have reverted to single polygon.

[jameshiebert]

Why so?

[rod-glover]

Because I changed it without realizing it was important during that work. The code was originally adapted from Climate Explorer, which explicitly restricts polygons to just 1 (for reasons I do not remember at the moment). Code for that remained in place, and I used it, evidently erroneously. I think it's a simple matter to fix, not certain yet.

[rod-glover]

Resolved by #87