LDAP and/or Open ID Connect (OIDC) Authentication

[tbelway]

It would be awesome if LDAP and/or OIDC authentication (such as keycloak) could be implemented for central user management. I don't see any note of this in issues nor discussion so bringing it up here. It is very similar to THIS FEATURE REQUEST, except I'm adding LDAP to it. If you feel this is too similar and LDAP should instead be mentioned in the other discussion, feel free to close it, but I feel like it's different enough in implementation design that it should be a competitive alternative.