libvirt: rename all libvirt tests from virsh_* to virsh.*

This rename is useful for testers who wants to run only virsh tests
and don't wan't to write list of all available tests. Now to run
all virsh tests just execute './run -t libvirt --tests=virsh'.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
virt-libvirt: Remove all virt_test_type Params

Signed-off-by: Chris Evich <cevich@redhat.com>