Multipolygon overlapping issue

MultiPolygon doesn't support overlapping polygons:
explained [here](https://gis.stackexchange.com/questions/247923/overlapping-polygon-becoming-hole-when-converting-geojson-to-shapefile)
[official doc info](https://shapely.readthedocs.io/en/latest/manual.html#MultiPolygon)

Said in OCJ standard for MultiPolygon features :
[Downloadable PDF](https://portal.opengeospatial.org/files/?artifact_id=829) on page 22
>2.1.12 MultiPolygon
>A MultiPolygon is a MultiSurface whose elements are Polygons..
>The assertions for MultiPolygons are :
>1. The interiors of 2 Polygons that are elements of a MultiPolygon may not intersect.
>∀ M ∈ MultiPolygon, ∀ Pi, Pj ∈ M.Geometries(), i≠j, Interior(Pi) ∩ Interior(Pj) = ∅
>2. The Boundaries of any 2 Polygons that are elements of a MultiPolygon may not ‘cross’ and >may touch
>at only a finite number of points. (Note that crossing is prevented by assertion 1 above).
>∀ M ∈ MultiPolygon, ∀ Pi, Pj ∈ M.Geometries(), ∀ ci ∈ Pi.Boundaries(), cj ∈ Pj.Boundaries()
>ci ∩ cj = {p1, ….., pk | pi ∈ Point, 1 <= i <= k}
>3. A MultiPolygon is defined as topologically closed.
>4. A MultiPolygon may not have cut lines, spikes or punctures, a MultiPolygon is a Regular, >Closed point
>set:
>∀ M ∈ MultiPolygon, M = Closure(Interior(M))
>5. The interior of a MultiPolygon with more than 1 Polygon is not connected, the number of >connected
>components of the interior of a MultiPolygon is equal to the number of Polygons in the >MultiPolygon

This issue happens as I try to merge Polygons into a single MultiPolygon. That way I make one request and have multiple responses. As I make lots of requests, this hackish way allows me to reduce the number of requests thus gaining process time.

I would suggest to keep it like that to respect OCJ standard, but maybe add support for an official ‘multi-params’ support.
I would guess that support would be allowed by taking an array as parameter instead of a single object.

Start by reviewing the linked Shapely documentation and OGC MultiPolygon specification to confirm the validity constraints described. Then locate the API request handling and tests for polygon inputs; done should mean overlapping polygons are handled according to the chosen behavior and array-based multi-parameter support is defined and verified.

Written by the indexing model from the issue text.