Update the ObjectStoreProvider's CreateObjectFromFile to open stream and wrap usage in a using statement to ensure disposing of the stream

### Changes
- Update the __ObjectStoreProvider.CreateObjectFromFile__ to open stream and wrap usage in a using statement to ensure disposing of the stream
- Fixed the naming convention of the __ProviderBase__ protected properties
- Modified the __ObjectStoreProvider.CreateObjectFromFile__ and __ObjectStoreProvider.CreateObjectFromStream__ methods to move the identity object to the last parameter and make it optional.
    - Updated to tests to match