Remove HeraldConditionConfig

Summary: Ref T2769. Moves all traces of HeraldConditionConfig into Adapters.

Test Plan: Edited rules and used Test Console to exercise both affected code paths. Tried to save invalid rules to hit error pat.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2769

Differential Revision: https://secure.phabricator.com/D6679