Move non-core virsh API to tp-libvirt

[lmr]

This is the list of virttest.virsh APIs used by libvirt_vm:

from virttest.virsh import command
from virttest.virsh import attach_interface
from virttest.virsh import canonical_uri
from virttest.virsh import define
from virttest.virsh import destroy
from virttest.virsh import detach_interface
from virttest.virsh import domain_exists
from virttest.virsh import domblklist
from virttest.virsh import domid
from virttest.virsh import dominfo
from virttest.virsh import domjobabort
from virttest.virsh import domstate
from virttest.virsh import domuuid
from virttest.virsh import driver
from virttest.virsh import dump
from virttest.virsh import dumpxml
from virttest.virsh import is_alive
from virttest.virsh import is_dead
from virttest.virsh import migrate
from virttest.virsh import qemu_monitor_command
from virttest.virsh import restore
from virttest.virsh import resume
from virttest.virsh import save
from virttest.virsh import screenshot
from virttest.virsh import shutdown
from virttest.virsh import start
from virttest.virsh import suspend
from virttest.virsh import undefine
from virttest.virsh import vcpuinfo
from virttest.virsh import vcpupin

So, 29 functions that are necessary to the core. As of this writing, there are 179 functions that are implemented in virttest.virsh, meaning we could move 150 functions to tp-libvirt.