Add integration test-helpers and refactor integration tests

public/index.html

@@ -145,7 +145,7 @@
         Loading...
       </div>
 
-      <object type="image/svg+xml" data="assets/images/scenario_template.svg"></object>
+      <object id="map-resource" type="image/svg+xml" data="assets/images/scenario_template.svg"></object>
 
       <div id="status">
         <span id="hex-counter">Distance: <span id="hex-count">-</span></span>
@@ -246,7 +246,7 @@
     <script>
       const source = new EventSource('/esbuild');
       source.addEventListener('change', () => location.reload());
-      source.addEventListener('message', (e) => console.log(e));
+      // source.addEventListener('message', (e) => console.log(e));
     </script>
     <script src="index.js"></script>
     <script src="soldier_record_block.js"></script>