Supply Alert - Lock the "Nodes Impacted" drop down to non BSL users

Problem Statement

At the moment, any user can add additional markets, brands , sub Bu when accessing the "Nodes Impacted" drop down in the alert screen...even if they do not save or impact the alert...but gives the feeling that users can access and change (see screenshot enclosed)

Acceptance Criteria

Lock all the "Nodes Impacted" cells for edition to the people outsite of BSL