Added hashed tokens

app_database.sql

@@ -22,6 +22,7 @@ CREATE TABLE device_tokens (
     last_seen_at TIMESTAMP NULL DEFAULT NULL,
     last_successful_delivery TIMESTAMP NULL DEFAULT NULL,
     last_failed_delivery TIMESTAMP NULL DEFAULT NULL,
+    hashed_token VARCHAR(64) NOT NULL,
 
     CONSTRAINT fk_user FOREIGN KEY (user_id) REFERENCES users(user_id)
         ON DELETE CASCADE