Policy: Audit for mandatory tags on resources/resource groups

[Springstone]

Overview/Summary

This pull request includes several updates and additions to the Azure Landing Zones (ALZ) policies and documentation. The most important changes involve the addition of new custom policies for auditing mandatory tags, updates to policy definitions, and enhancements to documentation.

New Custom Policies:

• Added Audit-Tags-Mandatory policy to audit resources for mandatory tags, excluding resource groups.
• Added Audit-Tags-Mandatory-RG policy to audit resource groups for mandatory tags.

Documentation Updates:

• Updated ALZ-Policies-Extra.md to include descriptions for the new Audit-Tags-Mandatory and Audit-Tags-Mandatory-RG policies.
• Updated Whats-new.md to mention the addition of the new custom policies for auditing mandatory tags.

Policy Definition Updates:

• Updated the bicep version and template hash in policies.json to reflect the latest changes.

Testing URLs

Azure Public