The map view currently supports Points and LineStrings. Adding Polygons (non-convex, with holes) would complete the typical list of geospatial entity type, and would unlock, e.g., GeoJSON compatibility.

This requires:

• support for non-convex polygon with holes in re_renderer (part of Support more 2D primitives: ellipse, markers, text as in OpenCV #6012)
• ideally, support for transparency, as (large) opaque polygon would hamper map readability (Draw order & (order independent) transparency #702)