feat: retention policy for the postgres data or distinguish storage for hot and cold data

[geekbrother]

We don't have a retention policy for the subscriber_notification table and all processed messages are stored increasing the Postgres storage size. With the increasing messages throughput the storage size will grow a lot so we need to make a retention policy for the data in Postgres.

Upd. As we need to preserve the history data for users, we can possibly distinguish storage for hot and cold (history) data for performance and cost savings.