[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/engines/bing.py

@@ -38,7 +38,6 @@ import babel
 import babel.languages
 
 from searx.utils import eval_xpath, extract_text, eval_xpath_list, eval_xpath_getindex
-from searx import network
 from searx.locales import language_tag, region_tag
 from searx.enginelib.traits import EngineTraits
 
@@ -180,6 +179,10 @@ def request(query, params):
 
 
 def response(resp):
+    # pylint: disable=too-many-locals,import-outside-toplevel
+
+    from searx.network import Request, multi_requests  # see https://github.com/searxng/searxng/issues/762
+
     results = []
     result_len = 0
 
@@ -231,9 +234,9 @@ def response(resp):
 
     # resolve all Bing redirections in parallel
     request_list = [
-        network.Request.get(u, allow_redirects=False, headers=resp.search_params['headers']) for u in url_to_resolve
+        Request.get(u, allow_redirects=False, headers=resp.search_params['headers']) for u in url_to_resolve
     ]
-    response_list = network.multi_requests(request_list)
+    response_list = multi_requests(request_list)
     for i, redirect_response in enumerate(response_list):
         if not isinstance(redirect_response, Exception):
             results[url_to_resolve_index[i]]['url'] = redirect_response.headers['location']
@@ -272,16 +275,19 @@ def fetch_traits(engine_traits: EngineTraits):
 
 
 def _fetch_traits(engine_traits: EngineTraits, url: str, xpath_language_codes: str, xpath_market_codes: str):
+    # pylint: disable=too-many-locals,import-outside-toplevel
+
+    from searx.network import get  # see https://github.com/searxng/searxng/issues/762
 
     # insert alias to map from a language (zh) to a language + script (zh_Hans)
     engine_traits.languages['zh'] = 'zh-hans'
 
-    resp = network.get(url)
+    resp = get(url)
 
-    if not resp.ok:
+    if not resp.ok:  # type: ignore
         print("ERROR: response from peertube is not OK.")
 
-    dom = html.fromstring(resp.text)
+    dom = html.fromstring(resp.text)  # type: ignore
 
     map_lang = {'jp': 'ja'}
     for td in eval_xpath(dom, xpath_language_codes):