fix: playlist description and collaborative playlist rendering

falls back to the more "universal" microformat for description
extraction and provides limited support for collaborative videos
(no channel ucids or collaborator names)

ythdd_extractor.py

@@ -543,7 +543,7 @@ def WEBextractPlaylist(plid: str = "", ctoken: str = ""):
 	metadata = None
 	if not ctoken:
 		metadata = {
-			"header": safeTraverse(resp_json, ["header"]),
+			"microformat": safeTraverse(resp_json, ["microformat"]),
 			"sidebar": safeTraverse(resp_json, ["sidebar"])
 		}