[BugFix] - GR7 | V3 Incorrect messaging when Application Gateway but no SSL Certificates in a listener

[singhgss]

Overview/Summary

This Pull Request corrects the messaging displayed when an Application Gateway is present without any SSL certificates bound to its listeners. Previously, the workbooks would display an incorrect or unclear message, implying that the CA file had been processed but not indicating the absence of SSL listeners properly. This fix ensures that the message accurately reflects the scenario.

This PR fixes/adds/changes/removes

fixes #301

1. Fixes the incorrect messaging logic so that if there are no SSL certificates in any listener, a clear message is displayed.
2. Improves the certificate validation logic to perform a bidirectional check:
   • Validates if the certificate issuer is in or matches part of the Approved CA List.
   • Checks if the Approved CA is part of the issuer.

Breaking Changes

• None. The fix only changes the displayed messages and does not introduce breaking changes to logic or data structures.

Testing Evidence

• Verified by creating an Application Gateway without any SSL certificates in its listeners and checking the workbook messages. The resulting output now correctly indicates that CA file(s) were processed, but no SSL listeners were found.

As part of this Pull Request I have

• Checked for duplicate Pull Requests
• Associated it with relevant GitHub Issues
• Ensured my code/branch is up-to-date with the latest changes in the main branch
• Performed testing and provided evidence.
• Updated relevant and associated documentation.
• Ensured PowerShell module versions have been updated (manually or with the ./tools/Update-ModuleVersions.ps1 script).