Portal Accelerator Update: Defender for Cloud ARM template and AzFW AZs

[Springstone]

Overview/Summary

This PR introduces an ARM template to configure Defender for Cloud on all the subscriptions selected for ALZ as part of the deployment (instead of waiting on policy remediation). Additionally, also updated Azure Firewall availability zones selection to "all" by default, and included description for additional considerations.

This PR fixes/adds/changes/removes

1. New subscription template: mdfcConfiguration.json
2. Updates to eslzARM and eslz-portal

Breaking Changes

1. N/A

Testing Evidence

Testing URLs

Azure Public

As part of this Pull Request I have

• [X] Checked for duplicate Pull Requests
• [X] Associated it with relevant issues, for tracking and closure.
• [X] Ensured my code/branch is up-to-date with the latest changes in the main branch
• [X] Performed testing and provided evidence.
• [X] Ensured contribution guidance is followed.
• [X] Updated relevant and associated documentation.
• [X] Updated the "What's New?" wiki page (located: /docs/wiki/whats-new.md)