chore: extract node unique token to the separate resource

Link is readable by the users. As the token is sensitive it's better to
save it in some resource that is not readable by the `omnictl`.

Signed-off-by: Artem Chernyshev <[email protected]>

Author: Unix4ever

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

@@ -28,10 +28,7 @@ message SiderolinkSpec {
   // RemoteAddr is the machine address how it's visible from Omni
   // it is determined by reading X-Forwarded-For header coming from the gRPC API.
   string remote_addr = 8;
-  // NodeUniqueToken is the per node join token which is saved in the Node META partition after
-  // the machine is accepted in Omni.
-  // Only for Talos >= 1.6.
-  string node_unique_token = 9;
+  string node_unique_token = 9 [deprecated = true];
 }
 
 // LinkStatusSpec is created when the link peer event was submitted.
@@ -102,3 +99,10 @@ message ProviderJoinConfigSpec {
 message MachineJoinConfigSpec {
   JoinConfig config = 1;
 }
+
+message NodeUniqueTokenSpec {
+  // Token is the per node join token which is saved in the Node META partition after
+  // the machine is accepted in Omni.
+  // Only for Talos >= 1.6.
+  string token = 1;
+}