feat(dbus): Add support for configuring 'revpi-con-can' feature

Introduce the `configure_con_can` function to manage enabling,
disabling, status checking, and availability of the 'revpi-con-can'
feature. Update the `AVAILABLE_FEATURES` dictionary to integrate
'revpi-con-can' as a configurable feature.

src/revpi_middleware/dbus_middleware1/system_config/revpi_config.py

@@ -198,6 +198,34 @@ def configure_avahi_daemon(action: ConfigActions):
     return return_value
 
 
+def configure_con_can(action: ConfigActions):
+    revpi = RevPiConfig()
+    if action is ConfigActions.AVAILABLE:
+        return revpi.with_con_bridge
+
+    dt_overlay = "revpi-con-can"
+    config_txt = ConfigTxt()
+
+    if action is ConfigActions.ENABLE and revpi.with_con_bridge:
+        config_txt.clear_dtoverlays([dt_overlay])
+        config_txt.add_name_value("dtoverlay", dt_overlay)
+        config_txt.save_config()
+        subprocess.call(["/usr/bin/dtoverlay", dt_overlay])
+
+    elif action is ConfigActions.DISABLE and revpi.with_con_bridge:
+        config_txt.clear_dtoverlays([dt_overlay])
+        config_txt.save_config()
+        subprocess.call(["/usr/bin/dtoverlay", "-r", dt_overlay])
+
+    elif action is ConfigActions.STATUS:
+        return revpi.with_con_bridge and dt_overlay in config_txt.get_values("dtparam")
+
+    else:
+        raise ValueError(f"action {action} not supported")
+
+    return None
+
+
 def configure_dphys_swapfile(action: ConfigActions):
     return_value = simple_systemd(action, "dphys-swapfile.service")