Implement CuratorCannotCreateClassInFinalizedModelSpec

[johncross]

Use CreateDataModelPage, CreateDataClassPage, FinalizeDataModelPage.

[vijayshukla30]

@johncross
In this test case, there is an issue in the last step. In last step it says 'Verify that there is no left-hand menu and no 'Data Class' menu button | No Data Class menu button present in the Finalized version of the Data Model', but after finalizing Data Model we still have left menu and also Data Class menu.