[WIP] Kirigami 2

[jbruechert]

Kirigami 2 is out now for a few weeks, and it brings many improvements, especially in performance and style. This is just a a port to kirigami 2, with a few style improvements. You may wonder why there are maybe more deletions than additions, but it's just because I could remove some code and replace it by simpler kirigami build-ins (Mostly add the ListViews).

Please do not merge until Kirigami 2 is available from the plasma mobile repos.

I also styled up the ListView with icons, I hope it's no problem I do it in the same PR. Oh, and I simplified the Listview by removing the last edited date, I think it's easier to use on a mobile now, but I can change that back if you don't like that,
This is work in progress, and I will remove that label when I'm finished and everything should work.

EDIT: I think this is mostly finished, but it still needs some testing.