D23650: Add an icon for the trash root and a proper label

[Méven Car]

meven added a reviewer: broulik.

REPOSITORY
  R241 KIO

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D23650

To: meven, ngraham, #frameworks, broulik
Cc: broulik, kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns