Autofocus form control for adding TOTP codes

Summary: Ref D20122. This is something I wanted in a bunch of places. Looks like at some point the most-annoying one (autofocus for entering TOTOP codes) already got fixed at some point.

Test Plan: Loaded the form, got autofocus as expected.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D20128