feat: DTOSS-8458: Create a terraform module for azure action group

[mrlockstar]

Description

AB#DTOSS-8458

A Terraform module to provision azurerm_monitor_action_group resources, so we can standardise and streamline the creation of Azure Monitor Action Groups across our environments.

The module should support the following features:

• Setting the short name and full name of the action group.
• Adding various receiver types (email, SMS, webhook, etc.).
• Create an examples/ folder with a working example that demonstrates how to use the module, including:

Example variable values.
How to reference the module from an environment configuration.
Expected output.

https://dev.azure.com/nhse-dtos/dtos-service-insights/_build/results?buildId=17468&view=logs&j=ced2749f-787a-529b-d064-72b5c61df22f&t=a8ef944f-7917-542a-f805-14b39eb0c11c

https://dev.azure.com/nhse-dtos/dtos-service-insights/_build/results?buildId=17522&view=results

Context

Type of changes

• Refactoring (non-breaking change)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would change existing functionality)
• Bug fix (non-breaking change which fixes an issue)

Checklist

• I am familiar with the contributing guidelines
• I have followed the code style of the project
• I have added tests to cover my changes
• I have updated the documentation accordingly
• This PR is a result of pair or mob programming

---

Sensitive Information Declaration

To ensure the utmost confidentiality and protect your and others privacy, we kindly ask you to NOT including PII (Personal Identifiable Information) / PID (Personal Identifiable Data) or any other sensitive data in this PR (Pull Request) and the codebase changes. We will remove any PR that do contain any sensitive information. We really appreciate your cooperation in this matter.

• I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.