Update Releases page to use GraphQL endpoint

GraphQL is the new standard for our APIs at GitLab. This will improve reliability and stability of our Releases pages, by implementing GraphQL.

Update the project Releases page to use the GraphQL endpoint being created in #208702 (closed).

This switch should have no noticeable changes for end-users of this page in terms of usability or permissions/security.

No documentation is necessary for this change.

Edited May 11, 2020 by Jackie Porter