* feat: add LLMStructuredOutput and LLMStructuredOutputInvocation for structured output handling
- Introduced LLMStructuredOutput model class for structured output representation.
- Added LLMStructuredOutputInvocation class to handle invocation with structured output.
- Updated ModelInvocations to include LLMStructuredOutputInvocation.
- Modified InvokeType enum to support LLMStructuredOutput type.
* docs: update README.md to include support for LLM structured output in manifest versioning
Yeuoly