[WIP] Add LaVIN
# What does this PR do?
Adds the LaVIN model from - https://arxiv.org/pdf/2305.15023.pdf <br>
Model description - LaVIN is a vision-language instructed model that is affordable to train (it was trained in a few hours on 8 A100 GPUs) with good performance on ScienceQA.

Fixes issue #23846

## Who can review?

Models:
@amyeroberts @ArthurZucker 

** Draft ** (Maintainers and reviewers can go through the PR as and when needed, I will ping the reviewers once the PR is ready. Guidance/Questions/Concerns related to the PR are always welcome.
Hi @shauray8, thanks for opening this PR! 

The easiest and recommended way to make a model available in `transformers` is to add the modeling code directly on the hub: https://huggingface.co/docs/transformers/custom_models

This means, once working, the model can be found and used immediately without having to go through the PR process. We find this is a lot quicker as the bar for adding code into the library is high due to the maintenance cost of every new model, and so reviews take quite a while.<|||||>Hi @amyeroberts, That makes sense, I have not seen a lot of people use this particular model. I'll make all the necessary changes and add it to the hub. But if there's anything I can help with to improve HuggingFace I'm more than happy to do it.