Ability to delete or mark comments as spam

I did a big spam cleanup ahead of the upcoming migration.

The spam did stop about 6 months ago. We must have restricted commenting to confirmed users then.

Automatically closed - issue fixed for 2 weeks with no activity.

On May, 2023, the permission to post comments has been limited to confirmed accounts, as per #2599782: Remove access to create comments for unconfirmed users → .