Public transport platform quests aren't available if platform is a relation

[burrscurr]

Public transport platform quests (is there a bin, bench, shelter at this platform and similar) are not displayed for public_transport=platforms that are relations (typically type=multipolygon). Island platforms are often mapped as multipolygons, for instance, because the waiting area has an elevators, stairs to a passenger tunnel or similar within its perimeter. (I therefore consider this a bug rather than a feature request or a change).

This affects the following quests:

• AddBenchStatusOnBusStop.kt
• AddBusStopName.kt
• AddBinStatusOnBusStop.kt
• AddTactilePavingBusStop.kt
• AddBusStopLit.kt
• AddBusStopShelter.kt
• maybe AddBusStopRef.kt (this one just filters for nodes, maybe it also should for ways and even relations?)

I drafted a pull request extending the quests on relations: #5183.

How to Reproduce

1. Consider this relation which is a railway platform in the main station of a fairly large city. Note that this relation was last edited 2 years ago, and does not have lit, bench, bin or shelter tags.
2. Open the location of the relation in SC and download the area's data.
3. There are no quests displayed that refer to the platform relation.

Expected Behavior
SC should display quests related to platforms even if those platforms are multipolygon relations.

Versions affected

I checked this with v53.1.