Configurable backup region/failover option

[lnjohns]

It would be nice if there was driver configuration to handle a backup region in order to provide high availability using replicated secrets.

@willtong1234 proposes it nicely in this comment referenced below.

Originally posted by @willtong1234 in #88 (comment)

[jbct]

Hi lnjohns! Thank you for the enhancement request.

[Samia1117]

Any updates on this? For many organizations this will be a make or break feature for using this library. We can't afford a single region of failure