Putting secrets into environment variables is problematic due to them
being inherited by sub-processes, the ease as which these can be
leaked in logs, and the lack of support for loading secrets into
environment variables by systems such as systemd and docker.
Change the loading of secrets to be done by loading the content of a
file specified by an environment variable.
Use the useRuntimeConfig interface to read vapid details on the server
side. This is a more portale way to deal with loading data from the
environment in Nuxt.js.
