R1:0755482bf07b

Add transactions for installing/uninstalling applications

Summary: Fixes T11476.

Test Plan:
- Installed/uninstalled the Conpherence application
- Observed correct timeline stories
- Observed correct config in database
- Observed 404 for application page

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T11476

Differential Revision: https://secure.phabricator.com/D19339