Add log statement when starting plugin

Revert =

Contributes CURA-10475 and CURA-10625

cura/BackendPlugin.py

@@ -41,7 +41,7 @@ class BackendPlugin(PluginObject):
         if not self._plugin_command or "--port" in self._plugin_command:
             return self._plugin_command or []
 
-        return self._plugin_command + ["--port=", str(self.__port)]
+        return self._plugin_command + ["--port", str(self.__port)]
 
     def start(self) -> bool:
         """
@@ -52,6 +52,7 @@ class BackendPlugin(PluginObject):
         try:
             # STDIN needs to be None because we provide no input, but communicate via a local socket instead.
             # The NUL device sometimes doesn't exist on some computers.
+            Logger.info(f"Starting backend_plugin [{self._plugin_id}] with command: {self._validatePluginCommand()}")
             self._process = subprocess.Popen(self._validatePluginCommand(), stdin = None)
             self._is_running = True
             return True