* Add llmFramework build option to select between LLM backends
      (e.g., llama.cpp, onnxruntime-genai)
* Integrate llmFramework selection into native build via Gradle arguments
* Replace shell script with Python script for pushing models and configuration files
* Add ONNX Runtime specific configuration files (e.g., onnxConfigUser.json)
* Update README with LLM framework usage instructions and build options
* Update the referenced LLM repository commit to enable ONNX Runtime compatibility

Change-Id: Ie998213a79828fc647b8e9b371e6ab0bcb2b0f01
Signed-off-by: Yunus Kalkan <yunus.kalkan@arm.com>