Add example datasets and tests that show curved and partly parallel lines that should not match

[Robinlovelace]

[JosiahParry]

A bit more context to this scenario. We expect a match between opposing angle iff they are within DT of eachother.

[Robinlovelace]

I think there's a good example of this in the simple and complex datasets here: https://github.com/nptscot/rnetmatch/releases/tag/intersection_road

From a user perspective looking at 2 different roads, ideally they shouldn't ever match is my take. This is an example where splitting either feature into smaller pieces does not help.