Finish PolKit integration

This MR contains a series of commits that removes the disable on PolKit usage and fixes remaining bugs in it to provide a user experience that allows manipulating files that require administrative access to modify in a secure way.

To test:

[compile patch to your install location; for me it's ~/kde/usr]

source ~/kde/build/kio/prefix.sh

export KDE_FORK_SLAVES=1

sudo cp ~/kde/usr/share/polkit-1/actions/org.kde.kio.file.policy /usr/share/polkit-1/actions/

sudo cp ~/kde/usr/share/dbus-1/system-services/org.kde.kio.file.service /usr/share/dbus-1/system-services/

sudo cp ~/kde/usr/share/dbus-1/system.d/org.kde.kio.file.conf /usr/share/dbus-1/system.d/

sudo cp ~/kde/usr/lib64/libexec/kauth/file_helper /usr/lib64/libexec/kauth/ (might be /usr/libexec/kf5/kauth/ on some distros)

kdeinit5

dolphin [then navigate to / and try to create a file or folder]

Test cases

Single file

• Drag-and-drop move to /
• Undo dnd move to /
• Drag-and-drop copy to /
• Undo dnd copy one file to /
• Cut-and-paste to /
• Undo cut-and-paste to /
• Copy-and-paste to /
• Undo copy-and-paste to /
• Rename file on /
• Duplicate file on /
• Undo duplication of a file on /

Four individual files

• Drag-and-drop move to /
• Undo dnd move to /
• Drag-and-drop copy to /
• Undo dnd copy to /
• Copy-and-paste to /
• Undo copy-and-paste to /
• Cut-and-paste to /
• Undo cut-and-paste to /
• Rename four files on /
• Duplicate four files on /
• Undo duplicate four files on /

Single Folder full of stuff

• Drag-and-drop move to /
• Undo Drag-and-drop move to /
• Drag-and-drop copy to /
• Undo drag-and-drop copy to /
• Cut-and-paste to /
• Copy-and-paste to /
• Undo copy-and-paste to /
• Rename folder full of stuff on /
• Duplicate folder full of stuff on /

Miscellaneous

• Create folder on /
• Undo creating folder on /
• Create a file on /
• Undo creating a file on /
• Edit permissions for file on /
• Drag-and-drop copy file from Ark to /