js: drop stupidtable plugin.

This was only used on the saved search index. It let you click on column
headers to sort the table by that column. This doesn't make sense now
that saved searches are paginated.

app/javascript/packs/application.js

@@ -6,7 +6,6 @@ function importAll(r) {
 
 require('@rails/ujs').start();
 require('hammerjs');
-require('stupid-table-plugin');
 require('jquery-hotkeys');
 
 // should start looking for nodejs replacements