Show the correct delete icons in/out of the trash

Summary: The `edit-delete` and `edit-delete-shred` icons were use in the opposite way they should be. `edit-delete-shred` is for permanent deletion and when there is a trash, `edit-delete` is used for moving to the trash.

Test Plan:
Old
{F7504444}

{F7504451}

{F7504456}

New
{F7504464}

{F7504472}

{F7504478}

Reviewers: #vdg, #kde_pim_kmail, mlaurent, ngraham

Reviewed By: #vdg, mlaurent, ngraham

Subscribers: kde-pim

Tags: #kde_pim

Differential Revision: https://phabricator.kde.org/D24377