Keeping TreeView state with component in Go

I came back to the tree view prototype re-implemented in my Go UI framework. It really doesn't behave any differently, but I spent all evening reimplementing it to handle a more React-like data model, where we store authoritative state of the tree in Go with the component, load and save there, and then push that state to the jQuery component.

I wasted a ton of time just trying to find a way to reset the data in jsTree. I kept trying to recreate the element and then re-run the initialization JavaScript that had the data to load. It really didn't like this, but I didn't think of another way until later when I put the jsTree element outside the component, then removed the template and just directly started setting up and using the jsTree API from the Go component.

Then I had to hook up any change that happens in jsTree to reproduce that change in the data model in the Go component, saving, and re-rendering the component, which now just calls some JS to set and refresh jsTree.

Lastly I got localStorage persistence working so it's roughly where it was before, but now I have control over the nodes in Go and can store any extra data on them there instead of hacking jsTree to keep extra data on the nodes.