[kcms/virtualdesktops] Enable apply button when typing desktop name

Currently the apply button will only be enabled when you press enter or
change focus away from the text field which is somewhat inintuitive.

Instead enable the apply button as soon as the text changed.

BUG: 435014

src/kcmkwin/kwindesktop/package/contents/ui/main.qml

@@ -53,9 +53,12 @@ KCM.ScrollViewKCM {
 
                     readOnly: true
 
+                    onTextEdited: {
+                        Qt.callLater(kcm.desktopsModel.setDesktopName, model.Id, text);
+                    }
+
                     onEditingFinished: {
                         readOnly = true;
-                        Qt.callLater(kcm.desktopsModel.setDesktopName, model.Id, text);
                     }
                 }