Allow adding to a group by phone number

ts/util/libphonenumberInstance.ts

@@ -2,8 +2,34 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import libphonenumber from 'google-libphonenumber';
+import type { PhoneNumber } from 'google-libphonenumber';
 
 const instance = libphonenumber.PhoneNumberUtil.getInstance();
 const { PhoneNumberFormat } = libphonenumber;
 
 export { instance, PhoneNumberFormat };
+
+export type ParsedE164Type = Readonly<{
+  isValid: boolean;
+  userInput: string;
+  e164: string;
+}>;
+
+export function parseAndFormatPhoneNumber(
+  str: string,
+  regionCode: string | undefined,
+  format = PhoneNumberFormat.E164
+): ParsedE164Type | undefined {
+  let result: PhoneNumber;
+  try {
+    result = instance.parse(str, regionCode);
+  } catch (err) {
+    return undefined;
+  }
+
+  return {
+    isValid: instance.isValidNumber(result),
+    userInput: str,
+    e164: instance.format(result, format),
+  };
+}