R1:6146aefcd4df

Show fewer useless transactions when creating objects, especially with EditEngine forms

Summary:
Fixes T7661. Ref T9527.

When you create a task, especially with an EditEngine form, you currently get more noise than is useful. For example:

> alice created this task.
> alice changed the edit policy from "All Users" to "Community (Project)".
> alice added projects: Feature Request, Differential.
> alice added a subscriber: alice.

Transaction (1) is a little useful, since it saves us from a weird empty…