WIP: Import changes from gitlab/dda/python-terraform

[Th0masL]

This PR contains the changes to support Terraform version 1.x, that have been applied on the gitlab repository dda/python-terraform

[jerger]

I think, we should reflect all changes since june 21 in the PR ...

[Th0masL]

~Just to make sure I understand, you think we need to take any changes that has been applied on this repo since last time your forked it on gitlab, and re-apply them on top of your changes ?~

I've re-applied the changes since June 2021.

Let me know if you see any other thing missing

[jerger]

Reintegrated the upstream changes & got green tests