The code was vulnerable to SQL injection. Likely not a security issue due to
WMI SQL and other constraints but still lame. For example:

  virsh # dominfo \"
  error: failed to get domain '"'
  error: internal error: SOAP fault during enumeration: code 's:Sender', subcode
  'n:CannotProcessFilter', reason 'The data source could not process the filter.
  The filter might be missing or it might be invalid. Change the filter and try
  the request again.  ', detail 'The WS-Management service cannot process the
  request. The WQL query is invalid. '

This commit fixes the Hyper-V driver by escaping all WMI SQL string parameters.

The same command with the fix:

  virsh # dominfo \"
  error: failed to get domain '"'
  error: Domain not found: No domain with name "
Signed-off-by: NLadi Prosek <lprosek@redhat.com>