feat: Add check templates enabled middleware

packages/backend/src/helpers/check-templates-enabled.js

@@ -0,0 +1,12 @@
+import Config from '../models/config.js';
+import NotAuthorizedError from '../errors/not-authorized.js';
+
+export const checkTemplatesEnabled = async (request, response, next) => {
+  const config = await Config.get();
+
+  if (!config.enableTemplates) {
+    throw new NotAuthorizedError();
+  }
+
+  next();
+};