Add "request account" instead of just open or closed

When creating a hubs-cloud, in addition to have the ability to lock down accounts (pre-load them like we did for IEEE VR), but I would also like to have someone request an account (they "log in" but it tells them it's send a request to system, and the email goes to owner, and there is a control panel for accounts).

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/HUBS-1036)

No files, tests, or entry points are identified in the issue. First clarify the account-request flow, owner email notification, and control-panel requirements before locating the relevant implementation. Done should include a defined request state and the described owner workflow.

Written by the indexing model from the issue text.