refactor(js): avoid use of window.XXX and move to import/export

- change worker: do not cache html pages (not necessary)
- remove use of window.XXX and maximize import/export,
  this will provide more clarety,
  show circular dependencies + you will benefit IDE help

static/device-verify.html

@@ -48,7 +48,6 @@
     <div id="status-error" class="status error hidden"></div>
   </div>
 
-  <script src="/js/core/csrf.js"></script>
-  <script src="/js/views/device-verify/device-verify.js"></script>
+  <script type="module" src="/js/views/device-verify/device-verify.js"></script>
 </body>
 </html>