Implement s3 backend and move OIDC code

General MR

Summary

This MR is for implementing the use of s3 backend and Dynomadb table for state lock. It also moves the OIDC code for runner auth.

This can be updated from baseline as we progress to use .tfvars and .tfbackend files for different environment backends.

Relevant logs/screenshots

Linked Issue

Create AWS S3 Backend for Dev Automation EKS terraform

Upgrade Notices

(Include any relevant notes about upgrades here or write "N/A" if there are none)