Migrate from KHotkeys to KGlobalAccel for custom command shortcuts

[opl-]

As explained here, KHotkeys has been deprecated in favor of KGlobalAccel. As such, I've done some investigative work to determine what the "Add Command..." button does in the Shortcuts system settings menu.

Creating a new command creates a new .desktop file in ~/.local/share/applications/, containing the following:

[Desktop Entry]
Exec=test
Name=test
NoDisplay=true
StartupNotify=false
Type=Application
X-KDE-GlobalAccel-CommandShortcut=true

This file is then referenced in ~/.config/kglobalshortcutsrc:

[test-2.desktop]
_k_friendly_name=test
_launch=none,none,test

I believe the .desktop file can be named anything, as long as it is unique.

References:

• https://invent.kde.org/frameworks/kglobalaccel/-/issues/3