feat(frontend): add visual indicator to top lists

frontend/src/util/getMaxCount.ts

@@ -0,0 +1,11 @@
+interface TopListItemEntity {
+  count: number;
+}
+
+/**
+ * Get max count for top list. Returns at least 1 to make sure we do not run into issues
+ * with empty list (would normally return -Infinity) or 0 (could cause divide by zero error).
+ */
+export function getMaxCount(items: TopListItemEntity[]): number {
+  return Math.max(1, ...items.map(({ count }) => count));
+}