ch: use monitor socket fd to send restore request

ch: use monitor socket fd to send restore request

Instead of curl, use low-level socket connections to make restore api
request to CH. This will enable passing new net FDs to CH while
restoring domains with network configuration.

Signed-off-by: Purna Pavan Chandra <paekkaladevi@linux.microsoft.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>