Create mergeRequestApprovalStateUpdated GraphQL subscription

Create a GraphQL subscription called mergeRequestApprovalStateUpdated that will return a MergeRequest type which can include approvals related data. Triggering this subscription will be done separately.

This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.