Filters: Improve simplification for location map

[danieldegroot2]

What feature would you like to see added?

Was #419

Improve location simplification (for any input option) further, if possible. It is possible there are still cases where simplication is too agressive, ie. half of Kilkenny (ignore there are two place relations, use either place / census) is diagonally cut off, while its shape is an oval (or: elongated circle). It might be due to geometry/rounding/clustering/ other calculation mistakes

Perhaps it could use (also) some preset shapes to estimate with?

additionally, it could have 'retry' option

Also, for point-type places, it returns a triangle. There might be quite a few ways to improve simplifying them. ie. simplify to circle ( see also #838 ), option to use nearby object polygons if not directly in search.

Why would this be useful to you or other users?

Allow user to get relatively accurate shape to get started with.

Currently, user might be left to drawing polygon themselves instead.