Provide means to determine if bulk import was successful

One thing customers would like to be able to do is know whether a bulk import that was launched was successful. If a client launches a bulk import and then dies (a rare case, but it happens), there's no way to know if that bulk import completed or is still in progress. Possibly, if bulk import returned a transaction ID, they'd be able to inquire whether that transaction has completed. Not sure if think that's currently possible via the Java client, but operators do consistently monitor FATEs via the shell. It'd be nice to do that via the Java client so we can monitor programmatically.

See comments on [ACCUMULO-4807](https://issues.apache.org/jira/browse/ACCUMULO-4807) for more detail.

Linked to JIRA ticket [ACCUMULO-4807](https://issues.apache.org/jira/browse/ACCUMULO-4807)

Start by reviewing the Java client’s bulk-import entry point and the related discussion in ACCUMULO-4807. Compare how operators monitor FATEs via the shell with what the Java client exposes. Done means a client can determine whether a bulk import is still running or has completed after the launching process exits.

Written by the indexing model from the issue text.