* Add a fluent databinding API based on the Bind class.
* Add tests for new API.
* Add snippet with API usage.

Change-Id: Id172eda8013bf874e27d85778d1151633c26eb6f
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.ui/+/165425
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Lars Vogel <Lars.Vogel@vogella.com>
Reviewed-by: Marcus Höpfner <marcus.hoepfner@sap.com>