Line Editor shouldn't allow creating rotated two-point lines

Currently, two-point lines must always be unrotated. (angle=0) With Line Editor, we can techniically create a rotated two-point line, which leads to unexpected behaviors. Cc @dwelle

[dwelle]

Or, make the line editor prohibit deleting points less than three.

I wouldn’t go that path as it’s non-intuitive and prevents several use cases (e.g. you’re toying with a 3-point line and decide you want to get rid of the middle point).

If we removed, it’d still just be a temp solution as I don’t think we’d want to retain this arbitrary limitation. As such, let’s just fix the problem at hand instead of hacking it further.

[dwelle]

This is gonna be fun 😃. Isn’t it better to handle rotation for 2-point lines as we do elsewhere? Would simplify everything.