Rework and cleanup of VFS

Summary:
Removed queue manager; Part of cleaning VFS (WIP)

Maybe re-add it in future. But KDE has its one queue/nofify dialog for KIO jobs.

Removed KIOJobWrapper. Part of cleaning VFS (WIP)

Calculating space on non-local filesystem does not work because its running in a different thread.
It did now work before either.

Removed VirtualCopyJob. Part of cleaning VFS (WIP)

Support for copy/move to virt:/ filesystem is limited (as before).
And btw: moving to virt doesn't make any sense and is not possible. Currently it is the same as copying

Merged normal_vfs and ftp_vfs into default_vfs. Part of cleaning VFS (WIP)

This code is compiling but there are a lot TODOs, not everything is working and performance is terrible.
More progress later...

Rework and merge of move() and copy() in panelfunc. Part of cleaning VFS (WIP)

+ KrVFSHandler is singleton now and can create copy jobs.
Job signals should be handled in VFS

Removed PreservingCopyJob. Part of cleaning VFS (WIP)

Preserving option was never used, KIO always preserves attributes when copying.

Cleaning up vfs. Part of cleaning VFS (WIP)

Minor code cleanup. Part of cleaning VFS (WIP)

Moved all classes related to archive handling to new folder. Part of cleaning VFS (WIP)

Removed unused mime type detection switch. Part of cleaning VFS (WIP)

Simplify usage of vfs. Part of cleaning VFS (WIP)

Compiling, bugs are cleaned later...

Rework of entire vfs class and subclasses. Part of cleaning VFS

Big diff. This needs extensive testing.

Added TODO comments. Part of cleaning VFS

Reviewers: Krusader

Differential Revision: https://phabricator.kde.org/D3025