Refactor Terraform Widget to extension

What does this MR do and why?

This MR refactors the browser performance widget to utilize MR Widget Extensions

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Enable refactor_mr_widgets_extensions feature flag in rails console - Feature.enable(:refactor_mr_widgets_extensions)
2. Follow the docs. For the quick start:
   • you can clone the example repository
   • create personal token in settings
   • create a variable TF_VAR_gitlab_access_token with the token

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #338284 (closed)