feat: implement cordoning infra machines

Implement cordoning of infra machines, so that bare metal infra provider can temporarily stop managing the machine. This is required when user needs to do manual maintenance on machines.

Signed-off-by: Utku Ozdemir <[email protected]>

Author: utkuozdemir

client/api/omni/specs/infra.pb.go

@@ -47,8 +47,8 @@ message InfraMachineSpec {
   string wipe_id = 5;
 
   string extra_kernel_args = 6;
-
   string requested_reboot_id = 7;
+  bool cordoned = 8;
 }
 
 message InfraMachineStateSpec {