AzureRT PR S34

New cmdlets:
```
New-AzurePlatformExtensionCertificateConfig
New-AzurePlatformExtensionEndpointConfigSet
New-AzurePlatformExtensionLocalResourceConfigSet
Publish-AzurePlatformExtension
Remove-AzurePlatformExtensionEndpoint
Remove-AzurePlatformExtensionLocalResource
Set-AzurePlatformExtension
Set-AzurePlatformExtensionEndpoint
Set-AzurePlatformExtensionLocalResource
Unpublish-AzurePlatformExtension
```
Nit: KeyPair and PublicKey?