Improve the mapping between intersection branches and curves

[YuriSizov]

Currently the branches and curves are mapped using a clockwise order from the -Z direction (so, 12 o'clock if looked at from the top). This results in weirdness, though, then the top-facing branch is to the left of that line. When it's to the right, it's properly mapped to be the first branch, but when it's to the left it's mapped as the last branch, being in the 300+ degree area.

This doesn't make good usability and produces this:

We should try to identify that we want a top-facing branch to start the order and find the most appropriate out of all of them and use that as the initial direction instead of -Z. Similar problem needs to be solved for #7.