Extract components for rendering items on a map

[seadowg]

Work towards #7118
Blocked by #7165

Why is this the best possible solution? Were any other approaches considered?

This extracts a new shared component (MappableItemsDelegate) for rendering items (MappableItem) on a map along with test helpers for making assertions around this. This should support adding reference geometry to the geopoint/geopoly question UIs.

How does this change affect users? Describe intentional changes to behavior and behavior that could have accidentally been affected by code changes. In other words, what are the regression risks?

I think some brief testing of select one from map is fine here. The changes are all outside of the map implementations themselves so just testing with OSM is fine.

Before submitting this PR, please make sure you have:

• added or modified tests for any new or changed behavior
• run ./gradlew connectedAndroidTest (or ./gradlew testLab) and confirmed all checks still pass
• added a comment above any new strings describing it for translators
• added any new strings with date formatting to DateFormatsTest
• verified that any code or assets from external sources are properly credited in comments and/or in the about file.
• verified that any new UI elements use theme colors. UI Components Style guidelines

[grzesiek2010]

@seadowg do you want this PR to be tested or wait for #7235 and test everything together?

[seadowg]

@grzesiek2010 we can wait!