We were discarding shapes too aggressively for having a
larger area than a shape underneath.
Let's also try showing fewer disambiguation menus, in particular
always preferring items on the active layer when the candidates
include overlapping items of similar area on other layers.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/7949
1) Tests can't expect accuracies around 1 to work. PCBNew defaults
to 5000.
2) Tests shouldn't artifically expand tolerance just to match the
results.
3) Tests should guarantee that end point is on arc, not just close
to it.
4) Standard polygonization of a circle is inside so splitting the
error needs to increase radius, not decrease.
5) Special-case first and last points so that they're exact.
1) An actual distance of 0 is still a collision, even if the allowed
distance is 0.
2) Be consitent about edges and interiors. Everyone expect the edge
of a RECT to be part of the RECT; same with a CIRCLE. SHAPE_POLY_SET
shouldn't be any different. (And SHAPE_LINE_CHAIN was a split-
personality with the edge considered part of it for Collide() but not
for PointInside()).
The hittest needs to use distance calc rather than squared distance.
This also adjusts the radius value to be double as to avoid unneeded
loss of precision
The arc shapes need to connect with their adjacent points. By storing
the relevant points, we allow exact point matching on both ends of the
arc as well as localize point storage.
* Split up the thirdparty code into the thirdparty folder (#3637)
* Create a new kimath static library containing all the math functions
This is part of cleaning the build system for #1906.
