[youtube:tab] Support channel search

Fixes: https://github.com/ytdl-org/youtube-dl/issues/29071

yt_dlp/extractor/youtube.py

@@ -2666,6 +2666,17 @@ class YoutubeTabIE(YoutubeBaseInfoExtractor):
             'uploader_id': 'UCKfVa3S1e4PHvxWcwyMMg8w',
         },
         'playlist_mincount': 12,
+    }, {
+        'note': 'Search tab',
+        'url': 'https://www.youtube.com/c/3blue1brown/search?query=linear%20algebra',
+        'playlist_mincount': 40,
+        'info_dict': {
+            'id': 'UCYO_jab_esuFRV4b17AJtAw',
+            'title': '3Blue1Brown - Search - linear algebra',
+            'description': 'md5:e1384e8a133307dd10edee76e875d62f',
+            'uploader': '3Blue1Brown',
+            'uploader_id': 'UCYO_jab_esuFRV4b17AJtAw',
+        },
     }, {
         'url': 'https://invidio.us/channel/UCmlqkdCBesrv2Lak1mF_MxA',
         'only_matching': True,
@@ -3234,8 +3245,9 @@ class YoutubeTabIE(YoutubeBaseInfoExtractor):
     @staticmethod
     def _extract_selected_tab(tabs):
         for tab in tabs:
-            if try_get(tab, lambda x: x['tabRenderer']['selected'], bool):
-                return tab['tabRenderer']
+            renderer = dict_get(tab, ('tabRenderer', 'expandableTabRenderer')) or {}
+            if renderer.get('selected') is True:
+                return renderer
         else:
             raise ExtractorError('Unable to find selected tab')
 
@@ -3309,6 +3321,7 @@ class YoutubeTabIE(YoutubeBaseInfoExtractor):
                 try_get(data, lambda x: x['header']['hashtagHeaderRenderer']['hashtag']['simpleText'])
                 or playlist_id)
         title += format_field(selected_tab, 'title', ' - %s')
+        title += format_field(selected_tab, 'expandedText', ' - %s')
 
         metadata = {
             'playlist_id': playlist_id,