teiiddes-1387: 

The ModelWorkspaceManager did not contain the newly created project when we tried to add the model resource since this happens when a resource is added. Changed to use ModelerCore.getWorkspace().getRoot().findMember(location) to get the project or project folder. Also broke logic out into a separate method in ModelErCore since this was needed in several classes for view and source models (XML, Flat File, Relational).