This commit adds a new ChatService class to handle all chat-related operations, including steps and artifacts.
- Implemented methods for executing a step within a task (executeStep).
- Added functionality to retrieve details for a specific step (getStepDetails).
- Enabled listing all steps for a specific task with optional pagination (listTaskSteps).
- Laid groundwork for artifact uploading (uploadArtifact) and downloading (downloadArtifact), though these are not implemented yet.
By encapsulating these operations within the ChatService class, this commit provides a clean and centralized way to interact with the backend for chat functionalities, making the application more maintainable and easier to extend.
