cancel approval flow on frontend when request is abandoned by client

src/lib/queue.js

@@ -30,5 +30,15 @@ export default function() {
             
             return this.items.shift();
         },
+
+        find_remove(pred) {
+            for (let i=0; i<this.items.length; i++) {
+                if (pred(this.items[i])) {
+                    this.items.splice(i, 1);
+                    return true;
+                }
+            }
+            return false;
+        },
     }
 }