Product Visibility Rules Case Study: "Company ABC produces and sells packaged food products to businesses (i.e. B2B, no direct sales to consumers). The company is implementing a new eCommerce platform for its clients which will allow them to shop and do several self-service activities. Due to most (but not all) products being tailor made, when a given client logs into the solution and starts an order, they should see ONLY the products which are applicable for them. The business has requested from the implementation team that they want to have two different types of product restriction rules - one according to the Key Account servicing the client and one according to a combination of the trade channel (e.g. Supermarket, Cafe, Small family-owned shop, etc.) and the customer segment (Diamond, Gold, Silver, Bronze). It should be possible in each rule to define a list of products as well as a list of the applicable trade channels and customer segments OR applicable Key Accounts. The rules need to have a start and end date. When creating a new rule, if there are already existing active rules for any of the products listed in the rule being created or a rule for the same combination of main parameters (Key Account OR Trade channel/Customer segment) then the user must be alerted, and the creation of a duplicate rules should not be allowed. Please list the high level stories (title and high-level summary) that are necessary to cover this functionality (backend and frontend)