[Feature] App Group Panel with list view mode

[RokeJulianLockhart]

Per https://github.com/FireCubeStudios/StartStrikesBack/blob/a1281167860f272c81106ea5443aef4f1587039d/README.md#preview-:

...I expect that this software shall (by default, at least) utilize a grid to display favourite applications. However, I have no reason to use a grid - the application icons are of no importance to me. Use KDE's Application Launcher as an example:

...versus:

Really, I'd like a tree view though, since I want to be able to view the content of folders inline, like the Windows 7 & 10 Start Menus used to allow.

[FireCubeStudios]

Yes this is easily possible by either creating a custom shell or by adding a new app panel supporting listview. I guess I can make a listview style panel