Create a working dataloader

[namiyousef]

Create a working dataloader that takes input text and prepares it for the model.

Criteria:

• Needs to be parametrised so you can easily modify preprocessing settings
• Needs to be fast for loading and processing data

[namiyousef]

Closing issue, parametrisation will be added as a separate issue once we have a better idea of which models we'll be using. Currently should work for most HuggingFace models