[mod] Peertube: re-engineered & upgrade to data_type: traits_v1

- fetch_traits(): Fetch languages from peertube's search-index source code.

  [mod] Include migration of the request methode from 'supported_languages'
        to 'traits' (EngineTraits) object.
  [fix] old supported_languages_url is no longer valid since the sources
        has been moved to a different path.

- fixed code to pass pylint
- request(): complete re-implementation based on the API docs [1]
- response(): complete re-implementation, adds serveral fields missed before
- add source code documentation

[1] https://docs.joinpeertube.org/api-rest-reference.html#tag/Search/operation/searchVideos

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

searx/settings.yml

@@ -1758,9 +1758,8 @@ engines:
     engine: peertube
     shortcut: ptb
     paging: true
-    # https://instances.joinpeertube.org/instances
-    base_url: https://peertube.biz/
-    # base_url: https://tube.tardis.world/
+    # alternatives see: https://instances.joinpeertube.org/instances
+    # base_url: https://tube.4aem.com
     categories: videos
     disabled: true
     timeout: 6.0