QMAPS-2052 add transport icons in map labels

[xem]

Description

• Add public transport icons into map labels
• 3 icons max, excluding "WALK". 4th and more are omitted
• icons can be repeated (ex: bus > bus > bus)
• small, dark ">" icons between each
• maybe put the duration on the line below on mobile
• if more than 4 vehicles: put "..." in the middle (deprecated)
• UPDATE: replace "..." with a little square containing "+2", "+3", etc.
• We may need to adjust bbox padding on desktop

Screenshots

[bbecquet]

@xem I've pushed a commit with the label rendering in its own component, which was the intent of my first comment and is more maintainable. Let me know what you think of it, I'm interested in your feedback.
I haven't changed the visual result as it already looked nice :)