KGlobalAccel: multi-shortcuts to switch between activities

[Oleg Solovyov]

Hello.
I am preparing patches for make activities hotkeys stored without cutting.

But since KF 5.86 keys were broken in Kirigami (see bug 445277) and I need 
this bug to be fixed first.

Bisecting shows that f8e14f9c is bad but I can't see why it is related to my 
issue so I need some help in investigation what is going on and why.

Thanks.