loginUser method
Authenticate a user with the given jwt token.
Returns a ZendeskUser on success, or null if authentication failed.
Implementation
@override
Future<ZendeskUser?> loginUser({required String jwt}) async {
final result = await methodChannel.invokeMethod<Map>(
'loginUser',
{'jwt': jwt},
);
if (result == null) return null;
return ZendeskUser.fromMap(Map<String, dynamic>.from(result));
}