Adjust padding next to graph for big value labels

This is the first step for [#52344173]. This ensures the value labels on the left don't run out of the pane, but doesn't address the issue of the axis label overrunning the value labels.

https://www.pivotaltracker.com/story/show/52344173
Adjust position of axis label when value labels are long

This is the rest of [#52344173] - if the value labels are greater than 100, the axis label gets bumped left to stay out of their way.

https://www.pivotaltracker.com/story/show/52344173