[extractors] Use new framework for existing embeds (#4307)

`Brightcove` is difficult to migrate because it's subclasses may depend
on the signature of the current functions. So it is left as-is for now

Note: Tests have not been migrated

yt_dlp/extractor/viqeo.py

@@ -1,5 +1,3 @@
-import re
-
 from .common import InfoExtractor
 from ..utils import (
     int_or_none,
@@ -17,6 +15,7 @@ class ViqeoIE(InfoExtractor):
                         )
                         (?P<id>[\da-f]+)
                     '''
+    _EMBED_REGEX = [r'<iframe[^>]+\bsrc=(["\'])(?P<url>(?:https?:)?//cdn\.viqeo\.tv/embed/*\?.*?\bvid=[\da-f]+.*?)\1']
     _TESTS = [{
         'url': 'https://cdn.viqeo.tv/embed/?vid=cde96f09d25f39bee837',
         'md5': 'a169dd1a6426b350dca4296226f21e76',
@@ -35,14 +34,6 @@ class ViqeoIE(InfoExtractor):
         'only_matching': True,
     }]
 
-    @staticmethod
-    def _extract_urls(webpage):
-        return [
-            mobj.group('url')
-            for mobj in re.finditer(
-                r'<iframe[^>]+\bsrc=(["\'])(?P<url>(?:https?:)?//cdn\.viqeo\.tv/embed/*\?.*?\bvid=[\da-f]+.*?)\1',
-                webpage)]
-
     def _real_extract(self, url):
         video_id = self._match_id(url)