providers/hyperv: add script to read switches

plugins/providers/hyperv/scripts/get_switches.ps1

@@ -0,0 +1,8 @@
+# This will have a SwitchType property. As far as I know the values are:
+#
+#   0 - Private
+#   1 - Internal
+#
+$Switches = @(Get-VMSwitch `
+    | Select-Object Name,SwitchType,NetAdapterInterfaceDescription)
+Write-Output $(ConvertTo-JSON $Switches)

plugins/providers/hyperv/scripts/import_vm.ps1

@@ -2,7 +2,9 @@ Param(
     [Parameter(Mandatory=$true)]
     [string]$vm_xml_config,
     [Parameter(Mandatory=$true)]
-    [string]$vhdx_path
+    [string]$vhdx_path,
+
+    [string]$switchname=$null
 )
 
 # Include the following modules
@@ -41,8 +43,10 @@ $MemoryMaximumBytes = ($memory.limit."#text" -as [int]) * 1MB
 $MemoryStartupBytes = ($memory.size."#text" -as [int]) * 1MB
 $MemoryMinimumBytes = ($memory.reservation."#text" -as [int]) * 1MB
 
+if (!$switchname) {
     # Get the name of the virtual switch
     $switchname = (Select-Xml -xml $vmconfig -XPath "//AltSwitchName").node."#text"
+}
 
 # Determine boot device
 Switch ((Select-Xml -xml $vmconfig -XPath "//boot").node.device0."#text") {