Python: Add Durable Agent Wrapper code (#1913)

* add initial changes

* Move code and add single sample

* Update logger

* Remove unused code

* address PR comments

* cleanup code and address comments

---------

Co-authored-by: Dmytro Struk <13853051+dmytrostruk@users.noreply.github.com>

python/packages/core/agent_framework/azurefunctions/__init__.py

@@ -0,0 +1,29 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import importlib
+from typing import Any
+
+PACKAGE_NAME = "agent_framework_azurefunctions"
+PACKAGE_EXTRA = "azurefunctions"
+_IMPORTS = [
+    "AgentFunctionApp",
+    "DurableAIAgent",
+    "get_agent",
+    "AgentCallbackContext",
+    "AgentResponseCallbackProtocol",
+]
+
+
+def __getattr__(name: str) -> Any:
+    if name in _IMPORTS:
+        try:
+            return getattr(importlib.import_module(PACKAGE_NAME), name)
+        except ModuleNotFoundError as exc:
+            raise ModuleNotFoundError(
+                f"The '{PACKAGE_EXTRA}' extra is not installed, please do `pip install agent-framework-{PACKAGE_EXTRA}`"
+            ) from exc
+    raise AttributeError(f"Module {PACKAGE_NAME} has no attribute {name}.")
+
+
+def __dir__() -> list[str]:
+    return _IMPORTS