[fix] engine & network issues / documentation and type annotations

This patch fixes some quirks and issues related to the engines and the network.
Each engine has its own network and this network was broken for the following
engines[1]:

- archlinux
- bing
- dailymotion
- duckduckgo
- google
- peertube
- startpage
- wikipedia

Since the files have been touched anyway, the type annotaions of the engine
modules has also been completed so that error messages from the type checker are
no longer reported.

Related and (partial) fixed issue:

- [1] https://github.com/searxng/searxng/issues/762#issuecomment-1605323861
- [2] https://github.com/searxng/searxng/issues/2513
- [3] https://github.com/searxng/searxng/issues/2515

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/enginelib/traits.py

@@ -13,6 +13,7 @@ used.
 from __future__ import annotations
 import json
 import dataclasses
+import types
 from typing import Dict, Iterable, Union, Callable, Optional, TYPE_CHECKING
 from typing_extensions import Literal, Self
 
@@ -82,8 +83,7 @@ class EngineTraits:
     """
 
     custom: Dict[str, Union[Dict[str, Dict], Iterable[str]]] = dataclasses.field(default_factory=dict)
-    """A place to store engine's custom traits, not related to the SearXNG core
-
+    """A place to store engine's custom traits, not related to the SearXNG core.
     """
 
     def get_language(self, searxng_locale: str, default=None):
@@ -228,7 +228,7 @@ class EngineTraitsMap(Dict[str, EngineTraits]):
 
         return obj
 
-    def set_traits(self, engine: Engine):
+    def set_traits(self, engine: Engine | types.ModuleType):
         """Set traits in a :py:obj:`Engine` namespace.
 
         :param engine: engine instance build by :py:func:`searx.engines.load_engine`