Fix wasted space at certain width in stacktrace UI

* The "collapse" etc. buttons get shown below the search box and < << >> > from
  a certain width downwards.

* similar stacking for the date/type/value and the buttons at an even smaller width.

See #120

theme/static_src/tailwind.config.js

@@ -49,6 +49,9 @@ module.exports = {
     ],
     theme: {
       extend: {
+        screens: {
+          '3xl': '1920px',
+        },
         spacing: {
           '128': '32rem',
         },