Move from global.psql to global.psql.main and global.psql.ci

Summary

We currently have global.psql in values.yaml

We should move from global.psql to global.psql.main and global.psql.ci

Implementation guide

1. The values under global.psql are all empty, so it should be OK to remove those, and replace with:

  psql:
    main:
      # ...
    ci:
      # ...

2. Make sure that the pipeline passes
3. Update the docs in https://docs.gitlab.com/charts/charts/globals#configure-postgresql-settings

Stuck ? Ask @OmarQunsulGitlab, or @clemensbeck for help