Textual Rewrite

[yhsanave]

Now that Textual is updated and has documentation, I'd like to rewrite the entire app with it :). I originally planned to use textual for this but the lack of docs and performance issues prevented me from getting very far with it. The process should be much easier with a nice GUI instead of a series of prompts with no way to undo mistakes. Since we're dealing with bulk processing, you should still be able to do the entire process with the keyboard, but having mouse support will be nice.