R1:307a41e8957b

Rename "HeraldObjectAdapter" to "HeraldAdapter"

Summary: Ref T2769. The term "Object" is redundant.

Test Plan: grep

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2769

Differential Revision: https://secure.phabricator.com/D6655