What to display: the first non-empty declared field, else the feature's id.
Latitude of a position standing for the feature — the point itself, a line's middle vertex, or the centre of anything else's bounding box.
Longitude of the same position.
OptionalboundsBounding box of a line or a polygon, to frame it; absent for a point.
Layer the feature belongs to.
That layer's display label.
The feature's id (properties.id, else id), or null when it carries none — such a
feature can be framed from bounds or lat/lng, but not selected.
One feature found by LayerDataApi.search.
Its first three fields —
label,lat,lng, andboundswhen present — are the shape of an address-search result, deliberately: a search box listing addresses and features side by side, or a route computed to either, needs no second branch. The rest names the feature, so that LayerDataApi.focus can frame and select it.