Legend bins should be interactive, filtering map when clicked

[carlhiggs]

In this image,

each of these bins should show a mouse pointer on hover, and when clicked toggle filtering of the map to show only that category (perhaps shifts other bins to grayscale) or click again to view all.

Currently, it doesn't do that. But it would be a nice feature, and intuitively people expect to be able to do that kind of thing.

This was a user request received in our website feedback.

[carlhiggs]

This has now been implemented; e.g.

for a map like this:

when you select a legend cell, it filters on this, setting the filtered out cells to semi-transparent and grayscale:

This works both for fill and line layers for now:

When you click the previously selected legend cell a second time, the filter is removed: