proposal: Inject given ENV variables as ARG's

[danielschlegel]

Use case

As a developer i want to pass ARGS like i do with shell scripts.

Instead of passing ARGS explicitly to earthbuild I want earth-cli to load my ENV variables from my console context if they are defined as ARG.

Expected Behavior

# Earthfile
ARG MY_VAR

Terminal

MY_VAR=true OTHER=false earth +target # this should automatically set MY_VAR but not OTHER as ARG in earthbuild

instead of calling.

Terminal

earth +target --MY_VAR=true