Calculate AOI area in sphere instead of WebMercator

[majkshkurti]

Expected Behavior

There is a significant difference between the cartesian area calculated from the backend and the area of the measure tool in the client. The client uses Ol/Sphere.js method from OpenLayers, which is more accurate than Shapely.

Possible Solution

Shapely doesn't support CRS so a workaround can be doing the intersection in PostGIS or having a custom python method.