refactor(dbus): D-Bus interface management with cleanup support.

Introduced a `DbusInterface` base class with a `cleanup` method to
standardize resource cleanup for D-Bus interfaces. Modified
`InterfacePiControl` to inherit from it and implemented `cleanup` logic
for proper watchdog resource handling. Adjusted `BusProvider` to manage
multiple interfaces and ensure cleanup on shutdown.

src/revpi_middleware/dbus_middleware1/process_image/interface_picontrol.py

@@ -7,11 +7,12 @@ from logging import getLogger
 from pydbus.generic import signal
 
 from .process_image_helper import PiControlIoctl, ResetDriverWatchdog
+from ..dbus_helper import DbusInterface
 
 log = getLogger(__name__)
 
 
-class InterfacePiControl:
+class InterfacePiControl(DbusInterface):
     """
     <node>
         <interface name='com.revolutionpi.middleware1.picontrol'>
@@ -32,6 +33,9 @@ class InterfacePiControl:
         self.wd_reset_driver = ResetDriverWatchdog(self.picontrol_device)
         self.wd_reset_driver.register_call(self.notify_reset_driver)
 
+    def cleanup(self):
+        self.wd_reset_driver.stop()
+
     def notify_reset_driver(self):
         self.NotifyDriverReset()