Render edges only when hovering on a node

[brienna]

Is there a setting or existing code functionality to only show edges connected to a node when hovering on that node?

It would be a lot like what's happening in the Highlight nodes/links example, except that all the other edges would not be rendered at all. This would help reduce lag when panning and zooming through larger graphs with 500,000+ edges, while also allowing the visualization of edges when one would be interested in seeing them.

I don't think this is quite the same ask as in #504, since if we set the edges' opacity to 0, I believe they're still rendered, so the larger graph would still lag.

[vasturiano]

@brienna you can use .linkVisibility(link => ...) for this purpose.