TEIIDDES-1597 Remove the concept of extention properties for ViewImpl objects for virtual models
Added back in ViewImpl to physical model. Also refactored metamodel-specific information from base provider to their specific metamodel provider.
Fixes a problem where view was not valid for a physical model.
Merge pull request #110 from elvisisking/TEIIDDES-1597-2

Teiiddes 1597 Remove the concept of extention properties for ViewImpl objects for virtual models