Allow adding to a group by phone number

ts/util/uuidFetchState.ts

@@ -0,0 +1,19 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+export type UUIDFetchStateKeyType = `${'username' | 'e164'}:${string}`;
+export type UUIDFetchStateType = Record<UUIDFetchStateKeyType, boolean>;
+
+export const isFetchingByUsername = (
+  fetchState: UUIDFetchStateType,
+  username: string
+): boolean => {
+  return Boolean(fetchState[`username:${username}`]);
+};
+
+export const isFetchingByE164 = (
+  fetchState: UUIDFetchStateType,
+  e164: string
+): boolean => {
+  return Boolean(fetchState[`e164:${e164}`]);
+};