Refactor DSC_SqlSecureConnection private functions to public commands

Description

The integration test PostInstallationConfiguration.Integration.Tests.ps1 contains code that duplicates functionality from private functions in the DSC_SqlSecureConnection DSC resource. These private functions should be refactored into public commands to reduce code duplication and improve maintainability.

Private Functions to Refactor

The following private functions from source/DSCResources/DSC_SqlSecureConnection/DSC_SqlSecureConnection.psm1 should be converted to public commands:

Certificate Permission Management

• Get-CertificateAcl - Gets the ACL of the certificate private key
• Set-CertificatePermission - Grants service account read permissions to certificate private key
• Test-CertificatePermission - Tests if service account has read permissions to certificate private key

SQL Server Encryption Registry Configuration

• Get-SqlEncryptionValue - Gets the SQL Server SuperSocketNetLib registry path
• Get-EncryptedConnectionSetting - Gets certificate thumbprint and ForceEncryption settings from registry
• Set-EncryptedConnectionSetting - Sets certificate thumbprint and ForceEncryption in registry

Benefits

1. Reduce code duplication - Integration tests can use public commands instead of duplicating logic
2. Improve testability - Public commands can be unit tested independently
3. Better reusability - Other scripts and modules can leverage these commands
4. Simplified maintenance - Single source of truth for certificate and encryption configuration logic

Implementation Notes

• Follow DSC Community naming conventions for public commands (e.g., Get-SqlDscCertificateAcl, Set-SqlDscCertificatePermission, etc.)
• Add appropriate comment-based help with examples
• Create unit tests for all new public commands
• Update integration tests to use the new public commands
• Update the DSC resource to use the new public commands
• Add localized strings for any user-facing messages

References

• PR: https://github.com/dsccommunity/SqlServerDsc/pull/2303
• Comment: https://github.com/dsccommunity/SqlServerDsc/pull/2303#discussion_r2423795837
• Requester: @johlju