Add LDAP binding to lookup accounts rather than having to check through Drupal

When checking whether users exist, the source of truth should start and end with our LDAP instance. In Quarkus, the closest tool we have for LDAP is the Elytron LDAP binding, which only binds to the security context and doesn't allow raw lookups/queries. There's the possibility that we can latch into the system and do our own lookups, but I'm not necessarily counting on it.

The other option that is more straight forward would be to use something like UnboundID, which is a popular Java library for binding to LDAP. It's Apache licensed, and is still actively supported with the last release being 2-3 months ago. Unless the Quarkus option is easy, I prefer this option as we have no guarantee that classes won't move and change under the hood for Quarkus extensions, as they only guarantee certain things be present.

The goal here would be to take a standard query string and be able to query using it and a passed and sanitized input string, and be able to lookup users, as well as cache them for 5 minutes to allow fast response to changes, but reduce the impact of high request thresholds from our connected APIs. The sanitization is really important here, as we don't want to allow people to add on to our query in any way.