fix(geo-layers): TileLayer default autoHighlight

[Pessimistress]

Closes #8787

CompositeLayer by default auto highlights all sub layers, assuming they all share the same data. This is true for most layers except overridden in GeoJsonLayer (which selectively passes highlight down depending on the feature), and in tiled layers. The basic TileLayer does not have any knowledge of how renderSubLayers uses the data, therefore there isn't a default behavior that will work for every use case. However, it is safer (and more correct?) to only highlight the sub layer that is being picked, than to assume that all sublayers should be highlighted at the same picked index.

For discussion: this is technically a breaking change (bug originally introduced in a 8.8 patch #7650), is it ok to include it as a patch?

Change List

• Add picked sub layer to TileLayerPickingInfo
• Only auto highlight the picked sub layer

[ibgreen]

For discussion: this is technically a breaking change (bug originally introduced in a 8.8 patch), is it ok to include it as a patch?

No good sense for whether apps have come to rely on the buggy behavior, but there seems to be no easy way of getting back to that behavior should it be desired.

Perhaps it would help to include the upgrade-guide bullet, and doc update for the change into this PR?

[coveralls]

coverage: 90.01% (+0.008%) from 90.002%
when pulling 73ad676 on x/tile-layer-autohighlight
into fa029dd on master.

[Pessimistress]

there seems to be no easy way of getting back to that behavior should it be desired

That is correct. To highlight multiple layers simultaneously in a tile, you'll need to wrap them in a CompositeLayer.

The buggy behavior was introduced at the end of v8.8 timeframe, and part of 8.9.0-beta.2. I think most users of the TileLayer use GeoJsonLayer/BitmapLayer to render their tiles, and they shouldn't be affected either way.