[mod] addition of various type hints / engine processors

Continuation of #5147 .. typification of the engine processors.

BTW:

- removed obsolete engine property https_support
- fixed & improved currency_convert
- engine instances can now implement a engine.setup method

[#5147] https://github.com/searxng/searxng/pull/5147

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

searx/extended_types.py

@@ -30,6 +30,7 @@ import httpx
 if typing.TYPE_CHECKING:
     import searx.preferences
     import searx.results
+    from searx.search.processors import ParamTypes
 
 
 class SXNG_Request(flask.Request):
@@ -78,6 +79,8 @@ class SXNG_Response(httpx.Response):
        response = typing.cast(SXNG_Response, response)
        if response.ok:
           ...
+       query_was = search_params["query"]
     """
 
     ok: bool
+    search_params: "ParamTypes"