Add QA tests verifying that SHAPE_LINE_CHAIN::Simplify works correctly on polygons with many points representing curved edges. The tests use the reproduction case from issue #22597 where a rotated rounded rectangle was converted to explicit xy points. A rotated rrect maintains the arcs, so the curve is not able to be reduced until converted to a poly without arcs Fixes https://gitlab.com/kicad/code/kicad/-/issues/22597