Check for non-square buildings

[aawiseman]

I'm submitting a feature request

Brief Description

A flag for buildings that have corners that aren’t 90 degrees

[willemarcel]

We are using the relying on the iD validation.

[adiatmad]

These changesets are containing a lot of unsquared buildings. It will be great if OSMCha has ways to detect this sort of behaviour.

[martien-176]

In addition to the previous: maybe an OSMCha flag that would detect when square buildings are edited in such a way that their squareness would be lost.

[batpad]

This would need to be added as a Compare function in the osm-compare repository: https://github.com/mapbox/osm-compare

One can look at the comparators in https://github.com/mapbox/osm-compare/tree/master/comparators and make a new one to detect this kind of geometry change.

I made an issue on the osm-compare repository referencing this issue: mapbox/osm-compare#230

We should close this issue and follow up in the osm-compare repository / it would be great if someone is able to take a first stab at this.