Summary:
Ref T8726. This modularizes "Mark with flag", plus rebuilds transcripts in a more modern/flexible way. The big transcript stuff is:
- Transcripts are now translatable.
- Transcripts can now show multiple outputs from a single action. For example, an action like "add A, B, C to subscribers" can now say "added A; B is invalid; C was already subscribed".
Test Plan: {F637784}
Reviewers: chad, btrahan
Reviewed By: btrahan
Subscribers: joshuaspence, eadler, epriestley
Maniphest Tasks: T8726
Differential Revision: https://secure.phabricator.com/D13649
