[xdg-activation] Handle desktop file aliases
The desktop file name that is requested when creating the activation is not necessarily the desktop file name of the window that ends up activated
For example when starting kcm_colors the window that ends up activated is systemsettings
Another case is Okular, where clicking on a PDF in the file manager okularApplication.desktop is launched but org.kde.okular.desktop ends up being activated
We terminate startup feedback based on the desktop file name, so in those cases the feedback doesn't stop
In the general case there not very much we can do about that, but for some cases we can use the X-KDE-AliasFor desktop file property to check whether two desktop file names should be considered the same app