Use standard tag elements instead of "maniphest project tag" to show tags in list views

Summary:
Standardizes tag rendering in Maniphest and Maniphest/Diffusion list views.

(This might need some size/spacing tweaks, I tried to make it look reasonable.)

Test Plan: See screenshots.

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D9741