Refactor SSL/SASL admin integration tests to not use a custom authorizer

[tinaselenge]

This makes the test simpler to enable KRaft later.

It's unclear why a custom authoriser had to be used in the first place based on the commit made this change and tests seem to work without it. The initial ACLs required by the tests are created with a super admin client instead of AclAuthorizationAdmin which is part of the custom authorizer.

IDEMPOTENT_WRITE was added to the initial ACLs created in the SASL setup, because SSL and BaseAdmin tests that being extended or extending this class do not override the configuredClusterPermissions method therefore end up not matching the expected permissions set on the cluster initially. Overriding this method does not seem necessary otherwise.

Committer Checklist (excluded from commit message)

• [ ] Verify design and implementation
• [ ] Verify test coverage and CI build status
• [ ] Verify documentation (including upgrade notes)