Additiona fixes: API key validation and tool calling backward compatibility
- Fix API key validation in OpenAiApi builder
- Standardize API key validation using Assert.notNull
- Add backward compatibility support for FunctionCallback in tool calling
- Update integration tests to use LegacyToolCallingManager
Co-authored-by:Christian Tzolov <christian.tzolov@broadcom.com>
Signed-off-by: Ricken Bazolo <ricken.bazolo@gmail.com>
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>