Enforce SOCKS proxy setting in search engine plugins

Previously it require each plugin to import helpers.py to setup SOCKS proxy.
Now it is enforced by default for all plugins.
Also added a function for plugins to ignore/restore the socket to
default state.

PR #22554.

src/searchengine/nova3/nova2.py

@@ -1,4 +1,4 @@
-#VERSION: 1.48
+# VERSION: 1.49
 
 # Author:
 #  Fabien Devaux <fab AT gnux DOT info>
@@ -46,6 +46,16 @@ from multiprocessing import Pool, cpu_count
 from os import path
 from typing import Optional
 
+# qbt tend to run this script in 'isolate mode' so append the current path manually
+current_path = str(pathlib.Path(__file__).parent.resolve())
+if current_path not in sys.path:
+    sys.path.append(current_path)
+
+import helpers
+
+# enable SOCKS proxy for all plugins by default
+helpers.enable_socks_proxy(True)
+
 THREADED: bool = True
 try:
     MAX_THREADS: int = cpu_count()
@@ -182,11 +192,6 @@ def run_search(search_params: tuple[type[Engine], str, Category]) -> bool:
 
 if __name__ == "__main__":
     def main() -> int:
-        # qbt tend to run this script in 'isolate mode' so append the current path manually
-        current_path = str(pathlib.Path(__file__).parent.resolve())
-        if current_path not in sys.path:
-            sys.path.append(current_path)
-
         # https://docs.python.org/3/library/sys.html#sys.exit
         class ExitCode(Enum):
             OK = 0