GUI: wizard: Use constraints to bind to base FS in NFS template

Signed-off-by: Tim Serong <tserong@suse.com>
GUI: wizard: Require clientspec in exportfs template

Signed-off-by: Tim Serong <tserong@suse.com>
GUI: wizard: Clone NFSv4 root in NFS server workflow

Signed-off-by: Tim Serong <tserong@suse.com>