Add dialog for copying urls to external player for livestreams

Also for livestreams which are over whose other sources
aren't present or aren't ready yet.

youtube/yt_data_extract/__init__.py

@@ -9,4 +9,4 @@ from .everything_else import (extract_channel_info, extract_search_info,
 from .watch_extraction import (extract_watch_info, get_caption_url,
     update_with_age_restricted_info, requires_decryption,
     extract_decryption_function, decrypt_signatures, _formats,
-    update_format_with_type_info)
+    update_format_with_type_info, extract_hls_formats)