This patch adds support to KIO to preserve xattr of files and directories on copy or move.
Working for copy/move including overwrite and rename cases.
Not working for "write into" when coping folders have name conflict. I'm against adding to this user case as the name of the action don't imply overwrite.
The autotests are a wip.
Tested only on Linux.
`Relevant bug`: [[ https://bugs.kde.org/show_bug.cgi?id=116617 | 116617 ]]