Retrieves the underlying OLE DB Data Source object from the Shape provider.
HRESULT GetDataProviderDSO( IUnknown **ppDataProviderDSOIUnknown );
[out] A pointer to a pointer that returns the IUnknown of the underlying OLE DB Data Source object.
This method does not addref the interface pointer. If the caller plans to hold the pointer, the caller must do the required addref and release.