Add a way to see the files in the field archive.

[Sebanisu]

I know Deling does this pretty well. But I already have the field open. I just want to be able to look at it. Maybe even extract files. Because I want to be able to know what some of the files are named so I keep the convention consistent. :P

• View a list of the files inside the field archive.
  It's already open I just need to list the files out or something.
• Extract files from the field archive.
  This would involve asking for a directory and saving the selected file(s) to it.

[Sebanisu]

The function to just get stuff from FL was kinda broken. I fixed it I think. Added some tests.