JS Refactor + Spinning

I've refactored the JS into a statically served file (galaxy requires restart to find statically served files added to a viz. plugin), and tried to separate out some of the functionality for a future migration to common interactive environment framework.

Additionally in this release I've added JS Spinning, removing the delay/`time.sleep` steps previously introduced. I've found this to be a much more pleasant experience, and we can be much more confident that it's working as intended. This has incidentally fixed one of my other issues where I was unable to have `apache_urls && password_auth`, I'm willing to bet it was a sleeping/synchronous step issue between galaxy and docker starting.

TODO: Added informative error message/timeout to the JS wait step.