Add tracking events for promoted extensions

Created by: ryankscott

In order to track how valuable and used our features are we should introduce tracking for all the new extensions we've promoted. This would include:

• Git blame
  • Git blame enabled
  • Git blame disabled
  • Popup viewed
  • Popup clicked (unsure if there's an action here)
• Search exports
  • Search export performed (include the number of results exported)
  • Search export failed (include the number of results exported)
• Open in editor
  • Open in editor button clicked (including which IDE)
  • Preferred IDE set (including which one)
  • IDE configured (including which IDE, and all IDEs)