Adding workflow to check for policy build

[arjenhuitema]

Overview/Summary

Add a workflow to review PRs for policy updates and verify if the Bicep build has been run.

This PR fixes/adds/changes/removes

1. Adds .github\actions-pester\PolicyPesterTestHelper.psm1
2. Adds .github\actions-pester\Test-BuildPolicies.Tests.ps1
3. Adds .github\workflows\check-policy-build.yml
4. Updates ALZ policies with latest Bicep version

Breaking Changes

None

Test results

When bicep build has not been executed:

When bicep build was executed:

As part of this Pull Request I have

• Read the Contribution Guide and ensured this PR is compliant with the guide
• Checked for duplicate Pull Requests
• Associated it with relevant GitHub Issues or ADO Work Items (Internal Only)
• Ensured my code/branch is up-to-date with the latest changes in the main branch
• Ensured PR tests are passing
• Updated relevant and associated documentation (e.g. Contribution Guide, Docs etc.)

[Brunoga-MS]

LGTM