Add Plotly-like double-clicking behaviour to PlotListLegend

[bobular]

Note: this was originally a full screen map ticket. It is no longer needed, but I'll leave the ticket in because I think it's functionality that would be nice-to-have at some point.

Single click will check/uncheck an item (as is present behaviour)

Double-click on a checked item exclusively selects that item (leaves it checked and unchecks all others)
Double-click an unchecked item selects everything except that item (leaves it unchecked and checks all others)

Some kind of one-time message (on first ever single click before a double-click has been done) should alert the user to this functionality. A snackbar makes sense.

Should also have a enableDoubleClick prop to turn this feature on/off.

Low, possibly medium cost.