Improved the u2f flow

What does this MR do?

Improves the u2f flow to be less button-y. 😇

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

u2f integration is awesome and this better ux was an easy win

Screenshots (if relevant)

Automatically listening for device, with fallback button

Device error, with fallback button

Fallback UI

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #18556 (closed)