Maintain "deploying" state across challenge navigations in competitive Play view

[sei-bstein]

The core issue here is that the competitive "play" view doesn't currently have a great way to remember if a challenge is in the process of deploying or undeploying its vms. The effect of this is that if the user deploys a challenge, navigates away from it, and then come back before the deploy has completed, you won't see the loading indicator that the deployment is in process. the deploy will still happen, and the interface will still reflect that the challenge has deployed when it's finished, but under the current architecture, remembering that a deploy is in progress after you leave the view is hard. If you try to deploy again (because GBUI doesn't know that one is in progress), you'll get an error, but your challenge is still deploying, and the UI will update when it's done.
It's not ideal, though, and could cause mild confusion.