[FEATURE] LDAP integration for user management

[rburns-oscar]

Is your feature request related to a problem? Please describe.
We have been using a self-hosted Argilla instance for our AI projects and have found it to be a great platform for output review. It has contributed to the success of multiple projects, and we would like to scale to more projects and more users. However, the manual user management is a little clunky, and since many of our AI projects utilize sensitive data we need to be extremely cautious with our access management (these high security requirements are also a reason why we have chosen to self-host).

Describe the solution you'd like
For other self-hosted third party software, we've been able to integrate our LDAP server and use LDAP groups for role-based access control. For instance, we self-host ArgoCD, which leverages Dex to accomplish this integration. It would be great to be able to utilize a similar solution with Argilla.

Describe alternatives you've considered
We've been creating users with the api, auto-generating strong passwords and sending them over secure messages, however we are worried that as the number of users grows we could become more likely to make a mistake and open up an attack vector.