ENH: Add plots for generic and linear generic surfaces

Make format didn't work. Will run it after review and fixes.

rocketpy/plots/aero_surface_plots.py

@@ -409,3 +409,19 @@ def all(self):
         None
         """
         self.drag_coefficient_curve()
+
+
+class _GenericSurfacePlots(_AeroSurfacePlots):
+    """Class that contains all generic surface plots."""
+
+    def draw(self):
+        pass
+
+
+
+class _LinearGenericSurfacePlots(_AeroSurfacePlots):
+    """Class that contains all linear generic surface plots."""
+
+    def draw(self):
+        pass
+