NPUW: Three-model pipeline (#31460)
### Details:
- *Separated Vocab MatMul into additional model*
- *Called infer for additional model in LLMInferRequest*
### Dependencies:
- *OpenVINO GenAI PR* :
https://github.com/openvinotoolkit/openvino.genai/pull/2317
### Tickets:
- *EISW-165218*
### Note:
- *Regression was found with the PR in the previous merge, PR was
reverted, this regression got fixed in current PR*
---------
Co-authored-by: Dmitry Matveev <dmitry.matveev@intel.com>
