Update Open AI client to assistants v2

[raulraja]

This PR refactors the configuration of the Assistant class, introduces new model classes, and updates tool handling logic.

• Replaces fileIds with toolResources in various methods and data classes.
• Updates AssistantRequest and AssistantThread classes to support new configuration structure.
• Adds CreateAssistantRequestToolResourcesFileSearch class to handle file search tool resources.
• Introduces new status RunIncomplete in RunDelta.
• Updates OpenAI client configuration to use assistants=v2.
• Adds pricing support for gpt4o
• Aligns the project with the latest API version.