message: Add CORP, COOP and COEP HTTP headers manually
  (until supported via https://github.com/helmetjs/helmet/issues/176)
diff: @@ -172,6 +172,12 @@ app.use(featurePolicy({
  payment: ["'self'"]
  }
  }))
  +app.use(function (req, res, next) {
  + res.setHeader('Cross-Origin-Resource-Policy', 'same-site')
  + res.setHeader('Cross-Origin-Opener-Policy', 'same-origin-allow-popups')
  + res.setHeader('Cross-Origin-Embedder-Policy', 'require-corp')
  + next() // TODO Replace above manually set headers with helmet solution once supported (see https://github.com/helmetjs/helmet/issues/176)
  +})
  /* Remove duplicate slashes from URL which allowed bypassing subsequent filters */
  app.use((req, res, next) => {
  