D12986: [Trash KCM] Clean up and standardize UI to be in line with the KDE HIG

[Nathaniel Graham]

ngraham edited the test plan for this revision.

REPOSITORY
  R241 KIO

REVISION DETAIL
  https://phabricator.kde.org/D12986

To: ngraham, #dolphin, #frameworks, #vdg
Cc: abetts, rkflx, kfm-devel, kde-frameworks-devel, michaelh, ngraham, bruns