feat: New Python-based `terraform_fmt` hook to better support Windows

[ericfrederich]

Put an x into the box if that apply:

• [ ] This PR introduces breaking change.
• [ ] This PR fixes a bug.
• [x] This PR adds new functionality.
• [x] This PR enhances existing functionality.

Description of your changes

Fixes #648

How can we test changes

From a windows PowerShell or cmd.exe (i.e. outside of Git Bash, or any other Bash) in a repo with a terraform_fmt hook, run pre-commit run -a and it will fail with something like /bin/bash: .... : No such file or directory.

Change the hook from terraform_fmt to terraform_fmt_v2 and it'll work.

I've tested on Linux and Windows. I've made formatting changes to terraform code and verified that it updates the files in place properly. I have verified that with --args=-check the files are not updated and the hook fails as expected while showing on stdout the offending files.