[subchain] stop forcing unnecessary app component re-renders

[brandonfancher]

I notice that each update forces subscribed components to re-render. For example, the NavProfile component (when depending on ship) re-renders multiple times per second. This is not gonna be great for performance. My guess is that it's because the subchain library's returning a new object with every update.

In the subchain library query hooks, we should do deep compares and only return a new object when there are actual changes.