jw.pkg.cmds.distro.backend.*.*: Util -> BeXxx

Don't derive the Backend classes from distro-specifiy Util classes
anylonger, but from command-specific BeXxx base classes.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/cmds/distro/backend/BeDup.py

@@ -0,0 +1,16 @@
+# -*- coding: utf-8 -*-
+
+import abc
+from argparse import Namespace
+
+from .Backend import Backend as Base
+from ..CmdDup import CmdDup as Parent
+
+class BeDup(Base):
+
+    def __init__(self, parent: Parent):
+        super().__init__(parent)
+
+    @abc.abstractmethod
+    async def run(self, args: Namespace) -> None:
+        pass