Update thumbnail integration after rebasing the branch

assets/common/js/picwall.js

@@ -1,10 +0,0 @@
-import Blazy from 'blazy';
-
-(() => {
-  const picwall = document.getElementById('picwall_container');
-  if (picwall != null) {
-    // Suppress ESLint error because that's how bLazy works
-    /* eslint-disable no-new */
-    new Blazy();
-  }
-})();

assets/common/js/thumbnails.js

@@ -0,0 +1,7 @@
+import Blazy from 'blazy';
+
+(() => {
+  // Suppress ESLint error because that's how bLazy works
+  /* eslint-disable no-new */
+  new Blazy();
+})();