Storage service: save new AccountRecord fields to disk

ts/util/phoneNumberDiscoverability.ts

@@ -0,0 +1,15 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { makeEnumParser } from './enum';
+
+// These strings are saved to disk, so be careful when changing them.
+export enum PhoneNumberDiscoverability {
+  Discoverable = 'Discoverable',
+  NotDiscoverable = 'NotDiscoverable',
+}
+
+export const parsePhoneNumberDiscoverability = makeEnumParser(
+  PhoneNumberDiscoverability,
+  PhoneNumberDiscoverability.Discoverable
+);