Add tracks when "Jetpack powered" elements are tapped

[Gio2018]

Add the following events to the "Jetpack powered" elements:

• When a banner is tapped: jetpack_powered_banner_tapped; property: screen, indicates what was the source screen. Allowed values:
  • Stats
  • Notifications
  • Reader
  • Reader search
  • Activity log
  • Sharing
• When a badge is tapped: jetpack_powered_badge_tapped; property: screen, indicates what was the source screen. Allowed values:
  • Home
  • Activity detail
  • Reader detail
  • App settings
  • Notifications settings
  • Me
• When the "Try the new Jetpack app" button is tapped: jetpack_powered_bottom_sheet_button_tapped