Show a progress indicator while logging into approvals

[sandbergja]

User story

As an approvals user, I want some feedback after I click the "LOGIN with NetId" button, so I can know whether or not I need to try again.

It regularly takes 5 seconds for the CAS network connections to complete for me. I observed it take over 10 seconds for Nish! We currently don't give the user any feedback that the login is proceeding, which can be disorienting and give the impression that our site is going to be super slow. Of course, it would be nice to speed it up, but since the main bottleneck is the network requests to CAS, I don't think we make improve it substantially. So at least letting the user know that the authentication is in progress, and they don't have to re-click the button, would be a start.

Acceptance criteria

• This feature also informs me that it is in-progress when using Voice Over in Safari.
• I have checked this feature using one of the following browser extensions and confirmed that it does not add any level A or level AA issues:
  • axe dev tools
  • Lighthouse
  • Wave

Implementation notes, if any

Lux has a LuxLoader component that seems well-suited to this purpose.