Allow AD integration to filter LDAP groups

[nightkr]

Description

Fixes #691

This PR adds a new field additionalGroupAttributeFilters to OpaCluster.spec.clusterConfig.userInfo.backend.experimentalActiveDirectory:

apiVersion: opa.stackable.tech/v1alpha1
kind: OpaCluster
spec:
  clusterConfig:
    userInfo:
      backend:
        experimentalActiveDirectory:
          additionalGroupAttributeFilters:
            foo: bar

Any group must match all attributes specified here in order to be included in the UIF report.

Release Note

The OPA user-info-fetcher can now filter Active Directory group membership by LDAP attributes.

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [x] CRD changes approved
- [x] CRD documentation for all fields, following the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs/style-guide).
- [X] Helm chart can be installed and deployed operator works
- [x] Integration tests passed (for non trivial changes) - (we don't currently have test coverage for AD, but I have tested manually that it works)

# Reviewer
- [ ] Code contains useful comments
- [ ] Code contains useful logging statements
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated. Follows the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs/style-guide).
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added
- [ ] [Roadmap](https://github.com/orgs/stackabletech/projects/25/views/1) has been updated

[nightkr]

Putting the CRD change decision into RFC.

[sbernauer]

CRD and code LGTM. Let's wait for the decision

[sbernauer]

WDYT of calling it additionalGroupAttributeFilters instead of customGroupAttributeFilters?

[nightkr]

Accepted during the meeting, with @sbernauer's suggestion.

[sbernauer]

LGTM. Was waiting for you to resolve the conflicts ^^