R1:696498934c9d

Support edge transactions in ApplicationTransactions

Summary: Fixes T2655. Adds generic support for edge edits (e.g., membership or attached objects).

Test Plan: See next diff.

Reviewers: chad, btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2655

Differential Revision: https://secure.phabricator.com/D5434