Test Case Execution Progress Report - Export to ZIP - Chart data csv should include column heading

When exporting the Test Case Execution Progress report to a zip, the Chart Data csv does not contain column headings, which on its own makes it useless

Suggested behaviour

- View Test Case Execution Progress report
- Select 'Export to zip'
- Open 'Test Case Execution Progress Chart Data.csv'
- The exported csv should contain the column headings, it currently does not