Use ApplicationTransactions for Releeph product activity

Summary:
Ref T3549. Ref T3663.

• Use transactions for activate/deactivate.
• Rename some "project" -> "product".

Test Plan:

• Activated products.
• Deactivated products.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T3663, T3549

Differential Revision: https://secure.phabricator.com/D8634