Modernisation: Make member variables private in bufrdc_expanded_descriptors

src/accessor/grib_accessor_class_bufrdc_expanded_descriptors.h

@@ -25,8 +25,9 @@ public:
     void destroy(grib_context*) override;
     void init(const long, grib_arguments*) override;
 
-public:
-    // TODO(maee): make private
+private:
     const char* expandedDescriptors_;
     grib_accessor* expandedDescriptorsAccessor_;
+
+    grib_accessor* get_accessor();
 };