R1:571ec81dd95c

Modernize the top half of Maniphest

Summary:
Use modern elements: crumbs, header, action list, property list, tags.

No functional changes.

Test Plan: {F26934}

Reviewers: chad, btrahan, vrana

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D4153