[services] add pre commit hook for terraform files

Summary: Terraform has opinionated style conventions that we should follow, just so that our .tf files look consistent. This commit introduces a pre-commit hook to check the formatting and validity of our .tf files.

Test Plan: Tried to commit invalid terraform code and the hook was triggered

Reviewers: yayabosh, karol-bisztyga, ashoat

Reviewed By: yayabosh, ashoat

Subscribers: ashoat, palys-swm, Adrian, atul

Differential Revision: https://phab.comm.dev/D4527