Preview Data Action Should Let User Know When There Is Not A Default Teiid Instance Defined

If there is no default Teiid instance, the Deploy VDB action displays a dialog telling the user that they need to create one in order to deploy a VDB. The Preview Data action should also do this. The Preview Data action will also need to change it's enablement policy as it should now even be enabled when there is no default Teiid instance. It would also be nice if both actions provided access to the "New Teiid Instance" wizard.