Add missing timezone info in important places

Things like SQLAlchemy work correctly only for timezone-aware datetimes.
The returned TLObjects all have them, but those that are manually created
were missing them, so serializing the state into SQLAlchemy sessions failed.

telethon/tl/custom/draft.py

@@ -159,7 +159,7 @@ class Draft:
             self._raw_text = raw_text
             self.link_preview = link_preview
             self.reply_to_msg_id = reply_to
-            self.date = datetime.datetime.now()
+            self.date = datetime.datetime.now(tz=datetime.timezone.utc)
 
         return result