admin dashboard updates

[czue]

New Screenshot:

Changes:

1. Change the current clusters to donuts, which show the approved/pending/rejected breakdown of the visits in that cluster. This is mostly just changing from the previous cluster example to this one: https://docs.mapbox.com/mapbox-gl-js/example/cluster-html/, and then getting it working with our setup.
2. Add a loading state to the map. And make a few other minor tweaks.
3. Add some charts. You can view that set of changes here if you want Add charts to the dahboard #431
4. Migrate most of the JavaScript functions to a new external JS file.

(recommend reviewing all at once)

[czue]

I don't think the build failure is related, though let me know if I should look into it

[calellowitz]

I admittedly didn't look too closely at the JS but the rest looks fine. One question

[calellowitz]

How confident are you that you want UserVisit rather than CompletedWork (user visits can be combined to form a single completed work, which is the unit of payment). I think we typically view Completed Works as a unit of delivery instead of the form, since it can account for things a visit that includes 2 forms filled out at the same time that together mark a delivery.

[czue]

It's all using the same base queryset which I got from the superset dashboard's SQL, so I think it's right? Or at least, it's consistent with the superset view and itself.

But can definitely revisit this logic once the dashboard has been vetted by the team more.

[calellowitz]

Didn't mean to approve and I think "requesting changes" is the only way I can get back to a not approved state, but depending on the answer to the question will approve again.