Python: Workflow visualization. (#372)

* Workflow visualization.

* fix typing

* address comments

* update all samples

* Update fan in edge group visual

* fix quality check

* Update python/samples/getting_started/workflow/step_06_map_reduce.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* address comment

* Catch up with changes in workflow; add to_mermaid method

* Update examples

* fix test

* add installation guide to error messages

* Remove visualization for samples except for one.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Evan Mattson <35585003+moonbox3@users.noreply.github.com>

python/packages/main/agent_framework/workflow/__init__.py

@@ -28,6 +28,7 @@ _IMPORTS = [
     "RequestInfoMessage",
     "WorkflowRunResult",
     "Workflow",
+    "WorkflowViz",
     "FileCheckpointStorage",
     "InMemoryCheckpointStorage",
     "CheckpointStorage",

python/packages/main/agent_framework/workflow/__init__.pyi

@@ -26,6 +26,7 @@ from agent_framework_workflow import (
     WorkflowEvent,
     WorkflowRunResult,
     WorkflowStartedEvent,
+    WorkflowViz,
     __version__,
     handler,
 )
@@ -56,6 +57,7 @@ __all__ = [
     "WorkflowEvent",
     "WorkflowRunResult",
     "WorkflowStartedEvent",
+    "WorkflowViz",
     "__version__",
     "handler",
 ]