Add Finetune Support

In the late versions of llama.cpp there are ways to fine-tune the model using LoRA adapters: https://github.com/ggerganov/llama.cpp/pull/2632

However, either I missed it or are there no functions introduced in this PR imported into this project?

**Describe alternatives you've considered**
Sure it's always an option to use a CLI tool, but I guess Python binding can be useful.