fix focus loss on mazimize with BorderlessMaximizedWindows=true
We also have an "Hide Window Border" and "Fullscreen" shortcuts also suffering this.
The patch suggested here solves them all.
Steps to reproduce:
place cursor somewhere on decoration and provoke any action removing the decoration.
Mouse focus gets lost but not the keyboard one.
Alternative implementation is here 77ca1c78 but I still see implementation here as preferable, see my comments there.