Parallel lookups for strict retrieval

[paulalbert1]

Allow for parallel lookup to do multiple user IDs at a time and multiple lookups for a given ID.

This may incur additional costs.

We should put an option in application.properties to allow admins to turn this on and off.

[sarbajitdutta]

See if we can issue spring boot async to figure out if we can do parallel lookup for strict mode. This will improve response time and will be completely async.