Get rid of workspaces and data from terraform_remote_state [PoC]

[halfb00t]

This boilerplate has two major cons which prevent using it in more complex cases, like multi-account|multi-regional|multi-environment infrastructures:

• it uses data form remote state of the first module layer1-aws
• it relies on terraform workspaces in order to create different environments

So the idea is to decouple l1 and l2 modules making them independent. Terragrunt is used to transfer outputs between modules and to build more complex layouts for infrstructures