Feature/legend filter

[romsson]

• Filters the VisTK scatterplot based on legend's product category being clicked
• The legend visually reflects the current selection by highlighting the currently selected product
• The filter can be disabled by clicking on the currently selected legend key
• Current version does not support time change, text filter, page refresh, and also does not filter the table

[romsson]

• Code cleanup
• Works for network visualization

[makmanalp]

Rebasing the commits on top of latest changes to review properly.

[makmanalp]

So the filtering works great as far as I can see, but there is some trouble with tooltips after the filter is removed, e.g in industry scatters:

and another example with product ones where suddenly it behaves strangely after the filtering is removed:

It's almost like the filter remains for the tooltip/hover even after it's been removed and the other nodes are visible.

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Also, we probably should call this out of scope for this ticket, but it'd be cool to make it obvious that the legend is clickable.

[makmanalp]

Also, there is a build error that seems relevant (https://circleci.com/gh/cid-harvard/atlas-subnational-frontend/669): "TypeError: undefined is not an object (evaluating 'keyFilter.length')" when you go to the country profile.

[gregshap]

Good catch @makmanalp

One other small thing: when filtering the product space, its very hard to see the difference between the products that this place does vs does not do

[makmanalp]

JShint complaining about a missing semicolon here

[makmanalp]

So @romsson it's still the same trouble for me: after filtering by a category and removing the filter, the tooltip only shows for the previously filtered category (and starts becoming laggy but that's less of a concern right now).

E.g. see after I filter by chemicals and undo the filter, how the purple ones are the only ones that have tooltips:

[QuinnLee]

@makmanalp we should rebase these frequently so we don't loose the feature.