Require MFA implementations to return a formal result object when validating factors master
Summary: Ref T13222. See PHI873. Currently, MFA implementations return this weird sort of ad-hoc dictionary from validation, which is later used to render form/control stuff. I want to make this more formal to handle token reuse / session binding cases, and let MFA factors share more code around challenges. Formalize this into a proper object instead of an ad-hoc bundle of properties. Test Plan: - Answered a TOTP MFA prompt wrong (nothing, bad value). - Answered a TOTP MFA prompt properly. - Added new TOTP MFA, survived enrollment. Reviewers: amckinley Reviewed By: amckinley Maniphest Tasks: T13222 Differential Revision: https://secure.phabricator.com/D19885