Correct an issue where Maniphest's awful legacy "reports" UI was extra broken on merges

Summary:
See PHI66. See that issue for context. This UI is bad broken legacy junk, but was especially broken when reporting merges.

These do not currently generate a "status" transaction, so they were never counted as task closures. Pretend they're normal closures.

This is still wrong, but should be much closer to the real numbers. Specifically, if you merge a closed task into another task, it will incorrectly be counted as an extra close. This could result in negative tasks, but the numbers should be much closer to reality than they are today even so.

The "Facts" application (T1562) is the real pathway forward here in the longer term.

Test Plan:

• Moved my maniphest_transactions table aside with RENAME TABLE ....
• Created a new empty table with CREATE TABLE ... LIKE ....
• Reloaded reports UI, saw empty chart.
• Created, closed, and reopened tasks while reloading the chart, saw accurate reporting.
• Merged an open task into another task, saw bad reporting.
• Applied patch, saw the right chart again.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D18601