PLT-6108 adding extra params to push notifications (#6236)

* PLT-6108 adding extra params to push notifications

* PLT-6108 adding extra params to push notifications

model/push_notification.go

@@ -36,6 +36,10 @@ type PushNotification struct {
 	ChannelId        string `json:"channel_id"`
 	ChannelName      string `json:"channel_name"`
 	Type             string `json:"type"`
+	UserId           string `json:"user_id"`
+	OverrideUsername string `json:"override_username"`
+	OverrideIconUrl  string `json:"override_icon_url"`
+	FromWebhook      string `json:"from_webhook"`
 }
 
 func (me *PushNotification) ToJson() string {