load secrets/configs from environment while parsing compose model

[ndeloof]

As we load compose model with environment, resolve secrets and config values based on declared environment value. This allows a nested model loading (using include) to resolve such values based on configured env_file, not just top-level environment. when marshaling model to yaml/json resolved content is hidden if it was set by environment, to keep definition consistency

closes https://github.com/docker/compose/issues/11952