Python: Add support for Foundry Toolboxes (#5346)

* Add support for the Foundry Toolbox in MAF

Introduces a Foundry Toolbox integration: FoundryChatClient gains a
get_toolbox() helper plus select_toolbox_tools(), normalize_tools in
the core package flattens tool-collection wrappers (ToolboxVersionObject
and generic iterables, while leaving Pydantic BaseModel instances
alone), and the new agent_framework.foundry namespace re-exports the
toolbox helpers. Ships with unit tests, a sample, and a design doc.

azure-ai-projects is pinned to the public >=2.0.0,<3.0 range and the
lockfile resolves from public PyPI. The toolbox test module skips when
Toolbox* types are unavailable so CI stays green until the public 2.1.0
SDK lands. OMC tooling directories (.omc/, .omx/) are gitignored.

* Update to latest azure ai projects package

* Improve sample

* Rename ADR to 0025

* Update ADR

* Apply suggestion from @alliscode

Co-authored-by: Ben Thomas <ben.thomas@microsoft.com>

* Improve samples

* Update test

---------

Co-authored-by: Ben Thomas <ben.thomas@microsoft.com>

python/packages/foundry/pyproject.toml

@@ -26,7 +26,7 @@ dependencies = [
     "agent-framework-core>=1.0.1,<2",
     "agent-framework-openai>=1.0.1,<2",
     "azure-ai-inference>=1.0.0b9,<1.0.0b10",
-    "azure-ai-projects>=2.0.0,<3.0",
+    "azure-ai-projects>=2.1.0,<3.0",
 ]
 
 [tool.uv]