R1:3fde02004968

Make many actions require high security

Summary:
Ref T4398. Protects these actions behind a security barrier:

- Link external account.
- Retrieve Conduit token.
- Reveal Passphrase credential.
- Create user.
- Admin/de-admin user.
- Rename user.
- Show conduit certificate.
- Make primary email.
- Change password.
- Change VCS password.
- Add SSH key.
- Generate SSH key.

Test Plan: Tried to take each action and was prompted for two-factor.

Reviewers: btrahan

Reviewed By: btrahan…