[FIX] website_event_track_quiz: keep search filter on page change

Before this commit, following these steps:
- Have more than 30 attendees for an event
- Go to the event page
- Click on community
- Search for a letter that is in the +30 attendees names
- Go to the second page of search results

=> We lose the filtering of the attendees by the letter. This commit
allows to keep the filters when the user is on a result page and
changes page.

task-3058239

Part-of: odoo/odoo#105462

addons/website_event_track_quiz/controllers/community.py

@@ -47,7 +47,8 @@ class WebsiteEventTrackQuizCommunityController(EventCommunityController):
             elif not page:
                 page = 1
             pager = request.website.pager(url=url, total=user_count, page=page, step=self._visitors_per_page,
-                                          scope=page_count if page_count < self._pager_max_pages else self._pager_max_pages)
+                                          scope=page_count if page_count < self._pager_max_pages else self._pager_max_pages,
+                                          url_args={'search': search_term})
             values['visitors'] = values['visitors'][(page - 1) * self._visitors_per_page: (page) * self._visitors_per_page]
         else:
             pager = {'page_count': 0}