Index Herald fields, not just actions, when identifying objects related to a particular Herald rule
Fixes T13408. Currently, when a package (or other object) appears in a field (rather than an action), it is not indexed.
Instead: index fields too, not just actions.
- Wrote a rule like "[ Affected packages include ] ...".
- Updated the search index.
- Saw rule appear on "Affected By Herald Rules" on the package detail page.
Maniphest Tasks: T13408
Differential Revision: https://secure.phabricator.com/D20795