Avoid duplicate line names #15
Description
When lines follow similar paths, they may end up with identical names today.
For example, take two transit lines forming a "Y" shape, where they both take the same road to the same district (the bottom of the Y) and split off to go to two destinations outside of any district (the tops of the Y). If the shared road accounts for most of the line's length, the road-and-district based naming algorithm will likely call them both "DistrictName via RoadName". That may be a reasonable name if there's only one such district, but if there are two, they should both be called something else.
One way to solve this would be to change the way the algorithm prioritizes name components. We have a set of possible components (district names, road names, etc.), and today we basically discard less relevant ones until the name is short enough to fit in the space allowed. Instead, we could discard less unique ones, so in this case we'd discard the common road and include the names of roads that are specific to each line.
However, this would mean potentially reassigning the names of all existing lines each time a new line is created.