"Add logging to backend plugin process"

This commit introduces logging to the backend plugin process in the Cura application. The output from the plugin process is now redirected to a log file, which is created in the application's data storage directory. This can be useful for debugging and troubleshooting purposes by providing more transparency about what's happening in the plugin process. A new dependency 'os' has been added to the 'BackendPlugin.py'. Also, the 'Resources' module has been imported from 'UM'. The changes mainly affect the way the 'subproccess.Popen' function is used - its 'stdout' and 'stderr' parameters were adjusted accordingly.

Contributes to CURA-11064

cura/BackendPlugin.py

@@ -1,6 +1,7 @@
 # Copyright (c) 2023 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 import socket
+import os
 import subprocess
 from typing import Optional, List
 
@@ -10,6 +11,7 @@ from UM.Settings.AdditionalSettingDefinitionAppender import AdditionalSettingDef
 from UM.PluginObject import PluginObject
 from UM.i18n import i18nCatalog
 from UM.Platform import Platform
+from UM.Resources import Resources
 
 
 class BackendPlugin(AdditionalSettingDefinitionsAppender, PluginObject):
@@ -75,10 +77,17 @@ class BackendPlugin(AdditionalSettingDefinitionsAppender, PluginObject):
             # 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()}")
-            popen_kwargs = {"stdin": None }
-            if Platform.isWindows():
-                popen_kwargs["creationflags"] = subprocess.CREATE_NO_WINDOW
-            self._process = subprocess.Popen(self._validatePluginCommand(), **popen_kwargs)
+            plugin_log_path = os.path.join(Resources.getDataStoragePath(), f"{self.getPluginId()}.log")
+            Logger.info(f"Logging plugin output to: {plugin_log_path}")
+            with open(plugin_log_path, 'a') as f:
+                popen_kwargs = {
+                    "stdin": None,
+                    "stdout": f,  # Redirect output to file
+                    "stderr": subprocess.STDOUT,  # Combine stderr and stdout
+                }
+                if Platform.isWindows():
+                    popen_kwargs["creationflags"] = subprocess.CREATE_NO_WINDOW
+                self._process = subprocess.Popen(self._validatePluginCommand(), **popen_kwargs)
             self._is_running = True
             return True
         except PermissionError: