sources: ldap uniqueness field per user and group

Hi,

**Is your feature request related to a problem? Please describe.**
We are using Authentik with LDAP in an organization, and it would be great to have the ability to set different object uniqueness fields for groups and users. Currently, we are using `uid` for users and `gid` for groups. We've been using 2 LDAP sources as a workaround, but this solution has a significant drawback: during synchronization, user-group mapping is lost until the next 'group LDAP source' synchronization.

**Describe the solution you'd like**
User has the ability to set 'User uniqueness field' and 'Group uniqueness field', which would then be used to extract values for the `ldap_unique` attribute.

**Additional context**
Finally we implemented temporary solution modifying `sources/ldap/sync` package.

Would You like to see a pull request with the feature?

**Version and Deployment**
authentik version: 2024.4.2
Deployment: docker-compose