Display data on RabbitMQ Status tab.

Using results from API calls to RabbitMQ server to display status info on Status tab.
There's a brief mention of `api-aliveness-test` at the bottom of that doc. It sounds like if that api call does not return `status: ok`, we should just stop there, not bother with calling any of the remaining api's, and display something to the user, such as the `host`, `user`, etc. info that we talked about this morning.