conf: rename structs used by Export function

conf: rename structs used by Export function

name structs to be the name of the Export function followed by Data
also tweak definitions to follow standard struct definition pattern

    ex. for virInterfaceObjListExport, the struct is defined as follows:

        typedef struct _virInterfaceObjListExportData virInterfaceObjListExportData;
        typedef virInterfaceObjListExportData *virInterfaceObjListExportDataPtr;
        struct _virInterfaceObjListExportData {...};

Signed-off-by: Anya Harter <aharter@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>