Honor preferContactAvatars field on AccountRecord

ts/util/areArraysMatchingSets.ts

@@ -0,0 +1,24 @@
+// Copyright 2020-2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+export function areArraysMatchingSets<T>(
+  left: Array<T>,
+  right: Array<T>
+): boolean {
+  const leftSet = new Set(left);
+  const rightSet = new Set(right);
+
+  for (const item of leftSet) {
+    if (!rightSet.has(item)) {
+      return false;
+    }
+  }
+
+  for (const item of rightSet) {
+    if (!leftSet.has(item)) {
+      return false;
+    }
+  }
+
+  return true;
+}