Render parent relation name rather than child relation name for routes

[StC-OSM]

Some routes (hiking, cycling, etc) are made of relations within relations, sometimes up to 4 to 5 levels of them. Often, each relation has a name only to indicate that it is a part of the parent relation.

When rendering, it is generally more appropriate to render the name of the parent relation. See for instance two images for parent relation 14900298 and its child relation 8413154, one from mapy.cz and the other from freemap.sk; the former corresponds more to what is usually expected on a map ("Voie de Vézelay" rather than "Voie de Vézelay, Brienne - Bar sur Seine" ; note that Tour des deux Bar is another route that goes through the same way there)

I have not checked how mapy.cz decides that a child relation corresponds to a route section, but it is plausible that they use the same criteria as what Waymarkedtrails states in its documentation: children relations with the same network tag are considered as sections of the parent relation. I wondered if you could consider using a similar rule.