server: implement messages and gRPC support for creating messages

server/api/response.go

@@ -49,3 +49,19 @@ func NewFilePayloadResponse(file *File) *FilePayload {
 func (f *FilePayload) Render(w http.ResponseWriter, r *http.Request) error {
 	return nil
 }
+
+func NewMessagePayloadResponse(msg *Message) *MessagePayload {
+	return &MessagePayload{Message: msg}
+}
+
+func NewMessageListResponse(messages []*Message) []render.Renderer {
+	list := []render.Renderer{}
+	for _, msg := range messages {
+		list = append(list, NewMessagePayloadResponse(msg))
+	}
+	return list
+}
+
+func (m *MessagePayload) Render(w http.ResponseWriter, r *http.Request) error {
+	return nil
+}