Pass the remember_me option into the u2f form and support it while authenticating

What does this MR do?

Adds remember me support in the u2f authentication, and makes sure the flag gets passed from the login form to the u2f form.

Based on the changes for the same thing done for regular 2fa: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4369

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

Where I pass the params and resource into the u2f render. Not sure if there is a better way to do this.

Why was this MR needed?

The remember me option wasn't working for u2f devices (yubikey)

What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18103

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 style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together

cc\ @dblessing