Fix handle loads in ManiphestTaskListView

Summary:
Fixes T4095. Fixes T3817.

  - The batch editor has some funky handle code which misses projects, share that.
  - Remove some hacks for T3817 that should be good now.

Test Plan: Looked at batch editor, saw projects. Looked at task list.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran, martin.schulz

Maniphest Tasks: T3817, T4095

Differential Revision: https://secure.phabricator.com/D7578