Default overlays near maneuver points

[ianthetechie]

I don't think this is high priority until someone comes along with an opinion / need for it, but creating the issue anyways. We theoretically already enable the user to add overlays (we allow arbitrary customization of the map via builders on both iOS and Android). But most navigation experiences have some sort of overlay like a white line (MapLibre Navigation, Organic Maps), a "pin" with a maneuver sign (can't remember where, but I've definitely seen this somewhere), etc. I assume we'll want to offer one that's reasonable out-of-the-box eventually.

Some examples:

MapLibre Navigation

Organic Maps