Remove a bunch of reundant checks for transactions with no effect from Maniphest

Summary: Ref T2217. These checks are no longer necessary, ApplicationTransactions handle them for us.

Test Plan:
  - Made a no-effect edit, verified no new transactions showed up.
  - Made real edits, saw them happen and leave transactions.
  - Made an edit which just reorders CCs, saw it detected as no-effect.
  - As above, with projects.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2217

Differential Revision: https://secure.phabricator.com/D7117