msggen: RequestStructs for notification-streams

I'm working to expose a stream of notifications over grpc.
This requries me to define structs that can be used to request
a stream of notifications.

These structs are all empty.

cln-rpc/src/notifications.rs

@@ -82,3 +82,27 @@ pub struct CustomMsgNotification {
     pub peer_id: PublicKey,
 }
 
+pub mod requests{
+use serde::{Serialize, Deserialize};
+
+    #[derive(Clone, Debug, Deserialize, Serialize)]
+    pub struct StreamBlockAddedRequest {
+    }
+
+    #[derive(Clone, Debug, Deserialize, Serialize)]
+    pub struct StreamChannelOpenFailedRequest {
+    }
+
+    #[derive(Clone, Debug, Deserialize, Serialize)]
+    pub struct StreamChannelOpenedRequest {
+    }
+
+    #[derive(Clone, Debug, Deserialize, Serialize)]
+    pub struct StreamConnectRequest {
+    }
+
+    #[derive(Clone, Debug, Deserialize, Serialize)]
+    pub struct StreamCustomMsgRequest {
+    }
+
+}

contrib/msggen/msggen/gen/grpc/convert.py

@@ -152,7 +152,7 @@ class GrpcConverterGenerator(IGenerator):
                 camel_case += word.capitalize()
         return camel_case
 
-    def generate_requests(self, service):
+    def generate_requests(self, service: Service):
         for meth in service.methods:
             req = meth.request
             self.generate_composite("requests", req)

contrib/msggen/msggen/gen/rpc/notification.py

@@ -45,3 +45,10 @@ class NotificationGenerator(IGenerator):
         for notification in service.notifications:
             _, resp_decl = gen_composite(notification.response, self.meta)
             self.write(resp_decl)
+
+        self.write("pub mod requests{\n")
+        self.write("    use serde::{Serialize, Deserialize};\n\n")
+        for notification in service.notifications:
+            _, req_decl = gen_composite(notification.request, self.meta)
+            self.write(req_decl, numindent=1)
+        self.write("}\n")