Update list of GPT models from OpenAI, including gpt-4o and removing some

[PabloReyes]

This pull request updates the supported OpenAI chat models and modifies the default chat model used in server configuration. The most important changes include updating the list of supported models and changing the default chat model to gpt-4o.

Updates to supported OpenAI chat models:

• packages/node/core/src/handlers/openai/types.ts: Updated the list of supported OpenAI chat models to include gpt-4, gpt-4-turbo, gpt-4o, gpt-4o-mini, and gpt-3.5-turbo.
• packages/node/core/src/handlers/openai/types.ts: Changed the default OpenAI chat model from gpt-3.5-turbo to gpt-4o.

Server configuration changes:

• packages/node/server/src/utils/createServer.ts: Updated the chatModel in middlewareConfig from gpt-4 to gpt-4o.