[Key Vault] Add error logging for when downloading an HSM's security domain fails.

[vcolin7]

Downloading an HSM's Security domain sometimes fails for our live tests without us logging a possible error message from the Powershell cmdlet. We can leverage .NET's approach to alleviate this in our test-resources-post.ps1 script. Here's a PR where Java added this change.

[gearama]

i'll look into it

[gearama]

we had this fix in our code