* Add a StateBag to AgentSession and pass Agent and AgentSession to AIContextProvider and ChatHistoryProviders
* Convert all AIContextProviders to use the statebag
* Update InMemoryChatHistoryProvider to use StateBag
* Update Comsos and Workflow ChatHistoryProviders
* Update 3rd party chat history storage sample.
* Remove serialize method from providers
* Replacing provider factories with properties
* Remove Providers from Session and flatten state bag serialization
* Update samples to use getservice on agent
* Updated additional session types to serialize statebag
* Fix regression
* Address PR comments
* Address PR comments.
* Fix formatting
* Fix unit tests
* Remove InMemoryAgentSession since it is not required anymore.
* Address PR comments
* Convert sessions for A2AAgent, ChatClientAgent, CopilotStudioAgent and GithubCopilotAgent to use regular json serialization.
* Fix durable agent session jso usgae
* Add jso to InMemory and Workflow ChatHistoryProviders
* Update InMemoryChatHistoryProvider to use an options class for it's many optional settings.
* Apply suggestions from code review
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Address PR feedback
* Fix verification bug.
* Improve state bag thread safety
* Address PR comments and fix unit tests
* Address PR comments
* Fix unit test
---------
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Move AgentSession.Serialize to AIAgent
* Address PR comments.
* Improve code and fix unit test
* Update test agents to return a default json element instead of throwing where the the result of the serialization is never used.
* Update further tests to actually serialize the session
