Give tokenizer tokens CSS color classes on the container instead of the icon

Summary:
Ref T4100. See D12465.

• Instead of putting CSS color classes on the tokenizer icons, put them on the container tags.
• Note that this removes the "bluegrey" default classes.
• This doesn't actually add CSS for the classes so, e.g., "green" doesn't make things green yet. This just supports D12465.

Test Plan: Viewed markup, saw classes.

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T4100

Differential Revision: https://secure.phabricator.com/D12467