Apply pts returned by some additional requests

When a bot account sends a message, deletes it, and sends a new one,
very reliably it would detect a gap, and as a result recover the
second message it sent, processing it itself (because the hack with
`_self_outgoing` cannot possibly work when catching up).

Now certain `rpc_result` are also processed as-if they were updates
(including the ones from deleting messages), which solves this gap
issue. Not entirely sure if it's a hack or the intended way to do it
(since Telegram *does* return proper `updates` for other RPCs), but
it seems to solve this particular problem.

Other requests such as reading history, mentions or reactions also
return an instance of this type, but the `pts_count` should be 0,
and at worst it should simply trigger a gap, which shouldn't be a
big deal.

telethon/network/mtprotosender.py

@@ -674,11 +674,28 @@ class MTProtoSender:
         _tl.UpdatesCombined.CONSTRUCTOR_ID,
         _tl.Updates.CONSTRUCTOR_ID,
         _tl.UpdateShortSentMessage.CONSTRUCTOR_ID,
+    )), _update_like_ids=frozenset((
+        _tl.messages.AffectedHistory.CONSTRUCTOR_ID,
+        _tl.messages.AffectedMessages.CONSTRUCTOR_ID,
+        _tl.messages.AffectedFoundMessages.CONSTRUCTOR_ID,
     ))):
         try:
             if obj.CONSTRUCTOR_ID in _update_ids:
                 obj._self_outgoing = True  # flag to only process, but not dispatch these
                 self._updates_queue.put_nowait(obj)
+            elif obj.CONSTRUCTOR_ID in _update_like_ids:
+                # Ugly "hack" (?) - otherwise bots reliably detect gaps when deleting messages.
+                #
+                # Note: the `date` being `None` is used to check for `updatesTooLong`, so `0` is
+                # used instead. It is still not read, because `updateShort` has no `seq`.
+                #
+                # Some requests, such as `readHistory`, also return these types. But the `pts_count`
+                # seems to be zero, so while this will produce some bogus `updateDeleteMessages`,
+                # it's still one of the "cleaner" approaches to handling the new `pts`.
+                # `updateDeleteMessages` is probably the "least-invasive" update that can be used.
+                upd = _tl.UpdateShort(_tl.UpdateDeleteMessages([], obj.pts, obj.pts_count), 0)
+                upd._self_outgoing = True
+                self._updates_queue.put_nowait(upd)
         except AttributeError:
             pass