Give "create" transactions a readable type in "transaction.search"
The "create" transaction is simple and straightforward, so label it to allow callers to distinguish it.
- Created a new task.
- Called transaction.search on it.
- Saw the labelled "create" transaction.
Reviewed By: amckinley
Maniphest Tasks: T13151
Differential Revision: https://secure.phabricator.com/D19505