[region-editor] Transition to Tcl/Tk for GUI #181

This allows for better control over window events and makes input handling
more consistent across platforms. It also allows better customization, for
example, the system undo/redo commands are used instead of key binds.

There is still much work to do, however this is a good starting point, and
has feature parity with the existing editor.

Author: Breakthrough

dist/requirements_windows.txt

@@ -4,6 +4,7 @@
 numpy
 opencv-python==4.10.0.84
 opencv-contrib-python==4.10.0.84
+pillow
 platformdirs
 pyinstaller>=6.0
 pytest