unify secrets names using Sensible Secrets scripts

follow up on: gitlab-com/gl-infra/k8s-workloads/gitlab-helmfiles!99 (comment 373237742)

One of the problems that Sensible Secrets is trying to solve is a unified naming convention for the secret files. If Sensible Secrets gets merged, we should follow up on it and rename the already existing secrets so that they follow the convention.