Feature: LLava executor

KernelMemory update with adding the use of already loaded model

When using KernelMemory one may have already loaded a model which can then be used with this extension instead of loading the model again.

[LLama.KernelMemory] Fixed System.ArgumentException: EmbeddingMode must be true & #617

Add an Example and modifications to the interactive executor to enable Llava Models.

Just a preview / demo

This reverts commit 5fda26c610.

Chat session state management