R1:4cbdd0c6e903

Refactor most uses of `AphrontFormDateControl` to user `AphrontFormDateControlValue`

Summary: Ref T8024, Refactor most uses of `AphrontFormDateControl` to user `AphrontFormDateControlValue`

Test Plan: Countdown and Phrequent should now save form data in error state.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T8024

Differential Revision: https://secure.phabricator.com/D12731