Move common utils out of conversation view

ts/util/markAllAsApproved.ts

@@ -0,0 +1,10 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { ConversationModel } from '../models/conversations';
+
+export async function markAllAsApproved(
+  untrusted: ReadonlyArray<ConversationModel>
+): Promise<void> {
+  await Promise.all(untrusted.map(contact => contact.setApproved()));
+}