The only user is now in qemu_monitor_json.c to re-parse the command line
format into keyvalue pairs for use in QMP command construction.

Move and rename the functions.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>