feat: add budget alert BB for GCP

[ishabakeh]

README.md

Having a Readme.md file is mandatory for every module. Please ensure that you include the following information inside the readme file:

1. Module Name and Description:

2. Provide a clear and concise name for the module.
   Include a brief description or summary of the module's purpose and functionality.
   How to Use this Building Block inside meshStack:

3. Explain how to effectively utilize this module within meshStack.
   Specify any required variables and inputs, along with their descriptions and usage instructions.
   Creating a backend.tf File:

4. Reference the related wiki page that explains how to create a backend.tf file.
   Include a link or provide clear instructions. For example: "You can find an example of how to create a backend.tf file on this Wiki Page."

5. Include any other pertinent details about the module.
   Consider adding information such as pricing details for the workload, if applicable, to help users better understand the module's implications.

Pull Request Description

Please provide a brief summary of the changes made in this pull request. And make sure to follow the regular naming conventions.

Related Issues

• List any related issues or references (e.g., Fixes #123).

Checklist

• I have tested these module locally and in meshStack.
• I have reviewed the code for formatting and style.
• I have updated the documentation if necessary.

Thank you for your attention to these documentation requirements.