for certain vertex features, only look at matching parent ways when determining where to draw direction cones:
* highway related points (e.g. highway=stop/yield/etc., traffic calming, cycleway=asl, traffic signs, barriers): only look at parent ways with highway=*
* railway related points (e.g. railway=milestone): only look at parent ways with railway=*
* waterway related points (e.g. waterway=milestone): only look at parent ways with waterway=*
see also #5634
- This is to make difference comparisons easier
- The only nodes that didn't have a `loc` were fake nodes we made for testing
- So this commit also fixes the `osmIntersection` code and tests.
This is used to draw vertices
* where multiple parent ways meet
* where a single way self intersects (but not the closing node of a loop)
We were using Graph#isShared or osmNode#isIntersection, but this is slightly
different to handle self-intersecting ways.
