fix: avoid empty applicationName in remote control dialog

This avoids having to display "An application has requested remote control" in remote control dialog in case an application does not have a desktop file. "An application" requesting permission makes it extremely difficult to judge for the user what is going on.

I could only find out that org.kde.krdpserver was requesting permission after applying this change. org.kde.krdpserver was requesting this permission on every start-up but I didn't know which application it actual was base on the previous dialog.

Before:

After:

Please tell me whether I should do this change in remotedesktopdialog.cpp and whether I should remote the isEmpty path in remotedesktopdialog.cpp entirely

    QString description = applicationName.isEmpty()
        ? i18nc("Unordered list with privileges granted to an external process", "An application requested access to:\n")
        : i18nc("Unordered list with privileges granted to an external process, included the app's name",
                "%1 requested access to remotely control:\n",
                applicationName);

Also, whether the application name should be quoted.