R1:a9604c4604b7

Update Fund for modular transactions

Summary: Fixes T12627. Updates FundInitiative and FundBacker with modular transactions.

Test Plan: Create an Initiative, back it with fake monies, close initiative, reopen, edit various fields.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T12627

Differential Revision: https://secure.phabricator.com/D17782