Make environment settings available in the project.yml

[wouterdb]

Goal

Make it possible for a project to indicate how it should be configured

E.g. by allowing it to override the defaults for the env settings

[sanderr]

What if this value is changed and an update is triggered? How do we know if we should update the setting value or not?

[sanderr]

Other question raised during planning meeting: how is config picked up? When the compile service pulls a new version, or when the compiler exports?