R1:587530a9bf7b

Add Standard Custom Fields to Item List

Summary:
Allow "Standard" (config-based") custom fields to be displayed in search-results.

Depends on D25548. Ref T15750.

Test Plan: Set `maniphest.custom-field-definitions` to the value of P32, and start playing with custom values on tasks.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: 20after4, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15750

Differential Revision…