Add libvirt API acl test case for virsh sendkey

Update virsh sendkey test case for test API 'send-input' in virDomainPtr
set.

Signed-off-by: Wayne Sun <gsun@redhat.com>
Add libvirt API acl test case for virsh screenshot

Update virsh screenshot test case for test API 'screenshot' in
virDomainPtr set.

Signed-off-by: Wayne Sun <gsun@redhat.com>