Arvados

When the user opens Workbench, the left and right sidebars should be exactly in the same state the user last left them. Right now we remember widths, but we don't remember collapsed/closed state. We should remember all of this.

Possible extension: we could save these values as user preferences in the Arvados API. Then Workbench would be able to present the same interface even if the user changes browser, etc. There are pros and cons to that, and it is more work. Needs discussion and consideration. We should decide whether or not we want to do this before we start work on the ticket.