[massive store] remove unused code

Drop a cw 3.24 warning

Fix unexpected req.relative_path() when calling CWTC.app_handle_request with path argument The _deprecated_path_arg decorator can not be used in this case, since it won't ensure backward compat if path value has been specified and is not similar as req's path (which is generally the case). This problem has been introduced by 904ee9cd0cf9.

[req,web/request] Move language prefix handling into web request This changes part of d8830e2bd2e0 by unsetting "lang" attribute of RequestSessionBase in particular (because it appears to break many downstream applications). The new implementation relies on a new "build_url_path" method on RequestSessionBase that is overridden in _CubicWebRequestBase to handle the language prefix in URL. As a consequence build_url in RequestSessionBase is not aware of this prefix anymore (contrary previous implementation from d8830e2bd2e0). Move respected tests from unittest_req.py into unittest_request.py. Commenting out part of test_handle_request_no_lang_negotiation_fixed_language in unittest_application.py because it now fails because of some obscure bug that cannot be resolved at the moment. Related to #15743487.

[test] Use stdlib unittest instead of lgc.testlib in unittest_request.py

[test] Distinguish "request" tests from accept parser ones in unittest_request.py

[pkg] Add setuptools to RPM build requirements

[pkg] Version 3.24.0

[req,web] Make it possible to handle page language from URL prefix Adding a short language prefix to URL (like "/en" or "/fr") changes the language the pages are displayed in. This prefix is kept during navigation. This way it is not necessary to do language negotiation, nor to use user preferences to determine which language to apply. This behavior is controlled through a new configuration option "language-mode", which replaces "language-negociation" option and which values may be "http-negotiation", "url-prefix" or "" (to disable language setting and force using "ui.language" property). Migration from previous option is not handled because I could not manage to have it working (users will get prompted with the configuration file diff anyways). Add some tests checking various scenarios. Closes #15743487

[config] fix the load_site_cubicweb() method for to 'new-style' cubes (closes #16059402) We first try to load the site_cubicweb module from the cubicweb_<cube> package, and if it fails, revert back to old cube path.