Improve consistency and Harbormaster integration of Diffusion

Summary:
Ref T9123. Two major Harbormaster-related UI changes in Diffusion:

• Tags table now shows tag build status.
• Branches table now shows branch build status.

Then some minor consistency / qualtiy of life changes:

• Picked a nicer looking "history" icon?
• Branches table now uses the same "history" icon as other tables.
• Tags table now has a "history" link.
• Browse table now has a "history" link.
• Dates now use more consistent formatting.
• Column order is now more consistent.
• Use of style is now more consistent.

Test Plan:

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9123

Differential Revision: https://secure.phabricator.com/D14242