MessageHistoryLimiter bug leading to incorrect order

[ekzhu]

          [autogen/agentchat/contrib/capabilities/transforms.py](https://github.com/microsoft/autogen/blob/0.2/autogen/agentchat/contrib/capabilities/transforms.py)

In MessageHistoryLimiter, line 99 of the file.
It should take _keep_first_message into consider. otherwise when keep_first_message==False , the last message will be inserted in a wrong place.

        # Loop through messages in reverse
        for i in range(len(messages) - 1, 0, -1):
            if remaining_count > 1:
                truncated_messages.insert(1 if self._keep_first_message else 0, messages[i])
            if remaining_count == 1:
                # If there's only 1 slot left and it's a 'tools' message, ignore it.
                if messages[i].get("role") != "tool":
-                   truncated_messages.insert(1, messages[i])
+                   truncated_messages.insert(1 if self._keep_first_message else 0, messages[i])

for example, following code output is in wrong order

from autogen.agentchat.contrib.capabilities import transform_messages, transforms


limiter=transforms.MessageHistoryLimiter(max_messages=3, keep_first_message=False)

limiter.apply_transform([{'role':'user', 'name':'agent', 'content':'0'},
                         {'role':'user', 'name':'agent', 'content':'1'},
                         {'role':'user', 'name':'agent', 'content':'2'},
                         {'role':'user', 'name':'agent', 'content':'3'},
                         {'role':'user', 'name':'agent', 'content':'4'},
                        ])

[{'role': 'user', 'name': 'agent', 'content': '3'},
 {'role': 'user', 'name': 'agent', 'content': '2'},
 {'role': 'user', 'name': 'agent', 'content': '4'}]

Originally posted by @milkmeat in #3178 (comment)