Please add undo capabiltiy in environment variable text windows

[hlovdal]

When reporting crashes, I do go through and filter/remove some details for privacy reasons. However if I accidentally delete too much, it's gone forever and impossible to bring back.

Can you please switching out the current editable text area window with one that has support for undo/redo (Ctrl-Z/Y keyboard shortcuts are sufficient)? I do not think this should be an extremely complicated task.