Python: Define Workflow and Executor APIs (#272)

* Workflow init commit

* Add samples and clean up

* ExecutionContext -> WorkflowContext

* Address comments 1

* Fix mypy

* flatting folder structure, and rename contexts

* Remove add_loop

* Add map reduce sample, remove Activation conditions

* Add AgentExecutor and allow multiple handlers per executor

* Minor improvement

* Add RequestInfoExecutor

* Add unit tests part 1

* Address comments 2

* Pre-commit update

* Add run method and more unit tests

* Add xml docs

* run_stream -> run_streaming

* message_handler -> handler

---------

Co-authored-by: Chris <66376200+crickman@users.noreply.github.com>
Co-authored-by: Evan Mattson <evan.mattson@microsoft.com>

python/packages/workflow/tests/test_edge.py

@@ -0,0 +1,47 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from dataclasses import dataclass
+from typing import Any
+
+from agent_framework.workflow import Executor, WorkflowContext, handler
+
+from agent_framework_workflow._edge import Edge
+
+
+@dataclass
+class MockMessage:
+    """A mock message for testing purposes."""
+
+    data: Any
+
+
+class MockExecutor(Executor):
+    """A mock executor for testing purposes."""
+
+    @handler
+    async def mock_handler(self, message: MockMessage, ctx: WorkflowContext) -> None:
+        """A mock handler that does nothing."""
+        pass
+
+
+def test_create_edge():
+    """Test creating an edge with a source and target executor."""
+    source = MockExecutor(id="source_executor")
+    target = MockExecutor(id="target_executor")
+
+    edge = Edge(source=source, target=target)
+
+    assert edge.source_id == "source_executor"
+    assert edge.target_id == "target_executor"
+    assert edge.id == f"{edge.source_id}{Edge.ID_SEPARATOR}{edge.target_id}"
+    assert (edge.source_id, edge.target_id) == Edge.source_and_target_from_id(edge.id)
+
+
+def test_edge_can_handle():
+    """Test creating an edge with a source and target executor."""
+    source = MockExecutor(id="source_executor")
+    target = MockExecutor(id="target_executor")
+
+    edge = Edge(source=source, target=target)
+
+    assert edge.can_handle(MockMessage(data="test"))