[feat] Add TextVQA dataset
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_3967). All of your documentation changes will be reflected on that endpoint.
This would be the first classification-based vision-and-language dataset in the datasets library.

Currently, the dataset downloads everything you need beforehand. See the [paper](https://arxiv.org/abs/1904.08920) for more details.

Test Plan:
- Ran the full and the dummy data test locally