In case safe config takes a long time to get committed, Atlas needs to retry and be able to poll the status of the current config in order to run the next reconfig command.
1. Run the next reconfig anyway and get a ConfigurationInProgress error if the previous isn't committed yet.
2. Add a dryRun option to reconifg, which only checks the commitment of the previous config without actually accepting the config.
3. Report in the response of replSetGetConfig if a new option is present.
4. Report the config status in replSetGetStatus.