AWS SCIM Groups cannot represent or read more than 100 members

## What

PUT/GET Groups cannot represent >100 members and cannot read current members (cleanup fails). Two symptoms, one AWS compatibility mode.

## Want

- PUT/GET Groups cannot represent >100 members
- Cannot read current members (cleanup fails)
- Two symptoms, one AWS compatibility mode

## Ideas this came from

- [#20410 provider/scim: AWS SCIM integration doesn't work properly with groups that contain 100+ members](https://github.com/goauthentik/authentik/issues/20410) — According to the AWS SCIM documentation, the API allows adding a maximum of 100 members in a single request: - https://docs.aws.amazon.com/singlesignon/latest/d
- [#23005 SCIM provider for AWS doesn't clean-up group members](https://github.com/goauthentik/authentik/issues/23005) — Authentik uses GET /Groups/ API call for reading current group members. According to AWS documentation, this method always returns an empty list. Thus, Authenti

Start with the SCIM Groups PUT/GET handlers and the AWS compatibility behavior described in issues #20410 and #23005. Verify the AWS limit of 100 members per request and the empty member list returned by GET /Groups/. Done means AWS Groups can represent more than 100 members and cleanup can determine current members reliably.

Written by the indexing model from the issue text.