Add an optional GUI using Gooey

[Ethkuil]

[fireattack]

Thanks!

Tested it, it works. I think it would be better if we use GooeyParser and add widget='FileChooser' to the original script, but that requires the user to install gooey, which is pretty heavy, even if they just want to use CLI.

I also have some trouble installing gooey due to two issues on wxPython:

1. wxPython 4.2.0 builds with Python 3.11 but can't find wx._core wxWidgets/Phoenix#2297 -- the current build has issues on Py3.11, which is fixed but hasn't been released
2. Installation with pip fails - cannot import name 'Mapping' from 'collections' wxWidgets/Phoenix#2236 or Pip install of wxPython 4.2.0 fails with python 3.11 wxWidgets/Phoenix#2296 -- users (in certain OS at least) need to manually install attrdict3 in order to be able to install wxPython

I solved them myself, but it would be confusing for others espeically newbies. So for now I will just merge it as-is.