[Feature]: Support for managing soft deleted API Management services

### Description of the new feature

There still does not seem to be a way to manage (list, purge, restore) soft deleted API Management services via Az PowerShell.

This issue was previously reported as https://github.com/Azure/azure-powershell/issues/14430. According to the discussion there, it should have been resolved in Az.ApiManagement version 4.0.2. However, I don't see any such functionality in the latest Az.ApiManagement module (currently at version 4.2.0), even though the Deleted Services objects are now exposed in a generally available REST API version (https://learn.microsoft.com/en-us/rest/api/apimanagement/deleted-services/purge?view=rest-apimanagement-2024-05-01).

### Proposed implementation details (optional)

_No response_

Start by examining the Az.ApiManagement module and the deleted-services REST API documentation linked in the issue. Identify the existing service-management entry points and verify how list, purge, and restore operations should be exposed; done means these soft-deleted API Management service operations are available through Az PowerShell.

Written by the indexing model from the issue text.