Fix Maniphest Reports scrolling issues

Summary: Fixes T7099, also picked some new colors. Raphael can bind the graph to a dom element, which resolved the scrolling issue.

Test Plan: Tested scrolling on my laptop, desktop. Seems resolved.

Reviewers: epriestley, btrahan

Reviewed By: btrahan

Subscribers: Korvin, epriestley

Maniphest Tasks: T7099

Differential Revision: https://secure.phabricator.com/D11879