History page column headers navigation and length cutoff

To summarize a discussion from a design sync meeting, we'd like to make the following changes to the column headers of the task and build variant history pages:

• The build variant and task history pages should link to one another via the column headers. Clicking a task name navigates to that task's history page, and clicking on a variant name navigates to that variant's history page:

• Long-winded column names should be truncated with ellipses. Hovering over the column name should give the full name. A proposed solution would be to put ellipses in the middle of the column name, showing the beginning and end of the name. We'll evaluate how users feel about this interface as part of user testing.