Add patch to disable dark mode on old windows

* patches/kguiaddons/
0001-DRAFT-There-is-no-dark-mode-on-old-Windows.patch: New.
* Makefile.am (EXTRA_DIST): Add patch.
* patches/kiconthemes/dark-mode-detection.patch: Add
Windows version check.

This disabled the dark mode detection based on the
users personalization configuration. It has no effect
on the High Contrast dark modes used for Accessibility.

As such the patch modifies kguiaddons to leave the
rest of the dark mode detection alone.

• GnuPG-Bug-Id: T7214