Perfect squares cannot be squared as they are not squarish

[rivermont]

Currently when a perfectly square way (such as this one) is attempted to be squared by either s or right click + square, it returns the message This can't be made square because it is not squarish.

This can be confusing as it obviously looks square and the user may experience an existential crisis as a result of being told a square is not squarish. This would seem to be a race case but it would be nice to have a condition of some sort that gives a different message or just squares it anyway.

[bhousel]

Ah yeah, this is because the code uses dot products to check for squareness, but a perfect 90° angle will have a dot product of 0.

I'm going to take a pass over the orthogonalizing code today and try to fix this and a few old related issues.. (#1979, #2472)

[quincylvania]

We should also be smart with feedback on straightening lines if they're already straight.

[bhousel]

We should also be smart with feedback on straightening lines if they're already straight.

Yeah - I almost put this into #5999 but I'm holding off until I merge #5740 to avoid conflicting @jguthrie100's work