Error message is unclear when updating secret which is being purged

[dingmeng-xue]

Description of the new feature

request comes from #14788

Create one secret, and then delete it. The secret is during purge. Then try to update secret again. It shows error but it's not clear to end user.

PS C:\dixue> Set-AzKeyVaultSecret -VaultName dixuekv0421 -Name foo -SecretValue (ConvertTo-SecureString "123" -AsPlainText -Force)
Set-AzKeyVaultSecret : Operation returned an invalid status code 'Conflict'
At line:1 char:1
+ Set-AzKeyVaultSecret -VaultName dixuekv0421 -Name foo -SecretValue (C ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : CloseError: (:) [Set-AzKeyVaultSecret], KeyVaultErrorException
+ FullyQualifiedErrorId : Microsoft.Azure.Commands.KeyVault.SetAzureKeyVaultSecret

We should show message which comes from server

Secret foo is currently in a deleted but recoverable state, and its name cannot be reused; in this state, the secret can only be recovered or purged.

Proposed implementation details (optional)