globalshortcuts: treat SysReq as Alt+Print

For shortcut purposes, treat SysReq as Alt+Print. This enables setting shortcuts like Alt+Print.

Known limitation: doesn't work on X11.

Also the displayed text in shortcut settings is still Alt,Alt+SysReq.

CCBUG: 386253

Depends on kglobalacceld!40 (merged) and frameworks/kglobalaccel!104 (closed).

@teams/qa