Outside edit operations get merged into one when undoing

[isidorn]

Refs: #33302

1. Have a file in vscode
2. Make an edit to that file in some other editor and save.
3. After some time make some other edit in the same file also in some other editor and save
4. Go back to vscode and undo, both edits from 2 and 3 get undone. In a perfect world the first undo would undo step 3 and only the second undo woul undo step 2.

Not a big deal imho