Preview raw 2d data

This adds the ability to visualize input data in the GUI before running a reduction. To accomplish this, I've added mantid as a dependency to the project so that we can use it's dataframes to mirror the example code that Yingrui shared with us. I had to update the local build instructions and the Dockerfile to work with conda/mantid as well.

The only other important note is that I think I've butchered the InputField class to support how I wanted to display things. If you are ok with the way things look, then I'd like to give some thought about how to refactor this better (maybe it's better to work on that in a separate issue?).

Leaving this as draft until I hear back from Yingrui, as I'd like him to confirm that this looks ok and figure out how to label the colorbar. Yingrui said it looks roughly correct. I added labels to the colorbars after reading his response, so I think this is ready for review.

Closes #16 (closed)