[Feature request] undo/redo support for editing text fields

[cenomla]

It would be nice if the GUI supported some basic undo/redo features.

Currently when you have a text field highlighted but aren't editing that field in the target properties window, and you press backspace it sets that field to empty and highlights the next field. You can easily accidentally delete all the settings you have for that target with no easy way to undo those changes.