Pan event into view on map

When an event is selected in the list, and that event is not currently visible on the map, we need to pan the map to event. In order to support the existing decoupled approach with state, the simplest solution seems to be to translate the current extent by the distance from the current center of the extent and the location of the marker, then update the extent in state. That should result in the map being updated to render the new extent.