Add RollbackToolRegistry in the Persistency feature in order to roll back tool calls with side effects when checkpointing. Make AIAgent state-manageable and introduce AIAgentService to manage multiple uniform running agents. Deprecate concurrent unsafe AIAgent.asTool in favor of AIAgentService.createAgentTool

Add RollbackToolRegistry in the Persistency feature in order to roll back tool calls with side effects when checkpointing. Make AIAgent state-manageable and introduce AIAgentService to manage multiple uniform running agents. Deprecate concurrent unsafe AIAgent.asTool in favor of AIAgentService.createAgentTool #138