Add ability to drag and drop objects in analyst view

[hazelshapiro]

See this tool, which has open source code: http://sankey-diagram-generator.acquireprocure.com/). What you do is:

1. navigate here
2. choose Load -> your own data from the menu (leftmost option)
3. paste the JSON code in and hit enter

Talk with @MattF-NSIDC about how difficult this would be to implement.

[mfisher87]

I've definitely looked at this before, but I don't remember everything we found. I searched for discussion in Slack and GitHub, but found nothing! D'oh!

They seem to have modified some other software (I believe in food.js), but it's not clear which parts are theirs and which aren't since the source isn't under version control.

In addition to the javascript we'd need to write to implement dragging and dropping, we'd also need to implement a mechanism to save the x,y positions in the database. This feature seems pretty expensive to me at a glance. Let's remember to revisit it later when we're fully funded, though.