Rename "binary authorization" category to "release governance"

This MR proposes that the Binary Authorization category be renamed to "Release Governance", so it is a more expansive category and not limited to one feature. The category will contain binary authorization, plus items like https://gitlab.com/gitlab-org/gitlab-ee/issues/8945#note_126671474 with the goal of ensuring that the deployment pipeline is always secure, compliant, and auditable.