This PR fixes up some issues with z-order manipulation that were noticed while using the scatter viewer in CosmicDS. Note that many of the changes here were based on the behavior of the bqplot scatter viewer.
Additionally, the viewers now retain other marks (e.g. those made by tools) when reordering the layers. Since there's no sensible general way to order these sorts of traces, they all just get push to the end of the trace list (higher z-index). If the tool that created these traces needs them in a particular order, it will have to sort that out itself. Note that the ordering of these non-glue traces relative to each other is left untouched.
This PR fixes up some issues with z-order manipulation that were noticed while using the scatter viewer in CosmicDS. Note that many of the changes here were based on the behavior of the bqplot scatter viewer.
Additionally, the viewers now retain other marks (e.g. those made by tools) when reordering the layers. Since there's no sensible general way to order these sorts of traces, they all just get push to the end of the trace list (higher z-index). If the tool that created these traces needs them in a particular order, it will have to sort that out itself. Note that the ordering of these non-glue traces relative to each other is left untouched.