refactor: Remove Request class and update decoder request handling

- Deleted the Request class from the runtime module, simplifying the codebase and reducing dependencies.
- Updated functions in CreateNewDecoderRequests to directly utilize LlmRequest, enhancing clarity and maintainability.
- Adjusted function signatures to accommodate the removal of the Request class, ensuring seamless integration with existing logic.

Signed-off-by: Robin Kobus <[email protected]>

Author: Funatiq