List Malware Scanner configurations

List the organization's Malware Scanner global configurations (presets): the named scan schedules applied to websites, each on the basic or the premium tier, with how many websites use each and which one is the default for new websites. The id is what the `preset_malware_scan` field of "Create connection plugin" (`POST /api/public/v1/connection-plugins`) takes, and what the requests under "Malware Scan Configurations" address: read one in full, create, edit or delete it, and assign websites to it there. Every row carries the same attributes as "Show malware scan configuration", under the keys the writes accept: `id`, `name`, `tier` (basic, premium), `status` (enabled, disabled), `is_default`, `schedule` (`frequency`, `start_hour`, `timezone`, `day_week`, `day_month`), `extensions`, `max_file_size` (bytes), `sites_count` (opt in with `fields[preset-malware-scans]=sites_count`), `created_at`, `updated_at`.