UI: AOI details page needs to leave breadcrumbs in the URL

[jkeifer]

Selecting items within the AOI via the sidebar tree on the AOI details page needs to change an element in the URL. Doing so will allow back/forward to navigate through what the user was looking at, and users can click away from the page and use back to get back to the thing they were looking at.

Some way to manage the state of expanded sidebar elements would also be nice, but I would be wary of adding too many state changes to the user's browsing history, to prevent making back/forward next to useless navigating through unnecessary intermediate states. Perhaps the URL could also include what elements in the tree are expanded, but only update on selection changes?