Allow hybrid builds

[nfroidure]

Currently, one can only build the server or target AWS Lambda/GCP Functions. Best would be to allow hybrid build, for example, to deploy the HTTP lambdas to ECS via a Docker container and consumer/cron lambdas to AWS Lambda.

It will require minor tweaks but will be very nice to have.

A way to achieve this would be to create build targets or to have several APP_ENV with builds varying accordingly.