Add alias for openai model clients

Author: jackgerrits

python/packages/autogen-ext/src/autogen_ext/models/__init__.py

@@ -0,0 +1,18 @@
+from typing_extensions import deprecated
+
+from .openai import AzureOpenAIChatCompletionClient as AzureOpenAIChatCompletionClientAlias
+from .openai import OpenAIChatCompletionClient as OpenAIChatCompletionClientAlias
+
+
+@deprecated(
+    "autogen_ext.models.OpenAIChatCompletionClient moved to autogen_ext.models.openai.OpenAIChatCompletionClient. This alias will be removed in 0.4.0."
+)
+class OpenAIChatCompletionClient(OpenAIChatCompletionClientAlias):
+    pass
+
+
+@deprecated(
+    "autogen_ext.models.AzureOpenAIChatCompletionClient moved to autogen_ext.models.openai.AzureOpenAIChatCompletionClient. This alias will be removed in 0.4.0."
+)
+class AzureOpenAIChatCompletionClient(AzureOpenAIChatCompletionClientAlias):
+    pass