Feature Request: allow import and export of filter polygons

[zstadler]

I'm submitting a feature request

Brief Description

Allow the import and export of filter's polygons.

What is the motivation / use case for this feature?

The built-in polygons associated with some locations are too coarse for filtering-out mapping activities beyond the real-life boundary. It is possible to draw a new polygon by one-self. However, as far as I know, with the current user interface:

• It is not possible to modify such a polygon
• It is not possible to share such a polygon with others
• It is not possible to draw multi-polygons
• It is not possible to draw holes in polygons

All of the above limitations can be addressed by allowing the filter's polygon to be exported and imported as GeoJSON, and the use of an external geometry editor.

Please tell us about your environment:

AFAIK, this applies to all browsers and operating systems