General: Allow Jetpack Manage Notice

- Added 2 banners.
- Notice on the Dashboard asking the user to opt in
This notice can be dismissed
- Second notice on the Jetpack and Jetpack Setting Screen
 User can’t dismiss the notice only with a filter.
- When the user opts in option gets activated + JSON API needs to get
activated.
- Still need to work on changing the wording.
- Update so that after the user connects we update the setting to JSON
API.