(CAT-1484) - Add ensurable property to resource

This commit adds a ensurable property to each resource which does
not already have an ensure property defined. This has a couple of
beneifts:

1. Prevents issues as seen in CAT-1484, where puppet namevars and DSC
   keys differences arise. By default, puppet will ignore namevar
   changes if they are the only atrtibutes passed in a manifest. This is
   a design of puppet and makes sure as namevars should only identify a
   resource. DSC's key values behave differently to this.
2. Will now clearly show in docs that the resource CANNOT be ensured.

The property sets a default of 'false' and will only accept values of
'False' or 'false'. The value will not need to be specified in
manifests.

src/Puppet.Dsc/internal/functions/Get-TypeContent.ps1

@@ -36,6 +36,24 @@ function Get-TypeContent {
       } Else {
         $FriendlyName = $Resource.FriendlyName
       }
+      # We add an ensurable property to all DSC resources that don't have an ensure property
+      $ResourceIsEnsurable = ($Resource.ParameterInfo | Select-Object -ExpandProperty Name).Contains('ensure')
+      $NotEnsurable = [pscustomobject]@{
+        Name              = 'ensurable'
+        DefaultValue      = 'false'
+        Type              = "Enum['False', 'false']"
+        Help              = 'Default attribute added to all dsc types without an ensure property. This resource is not ensurable.'
+        mandatory_for_get = 'false'
+        mandatory_for_set = 'false'
+        is_parameter      = 'false'
+        is_namevar        = 'false'
+        mof_is_embedded   = 'false'
+        mof_type          = 'String'
+      }
+      # We only add the ensurable property if it's not already present
+      If (!$ResourceIsEnsurable) {
+        $Resource.ParameterInfo += $NotEnsurable
+      }
       # It is not *currently* possible to reliably programmatically retrieve
       # the description information for a DSC Resource via CIM instances or
       # Get-DscResource or Get-Help.

src/Puppet.Dsc/internal/functions/Get-TypeParameterContent.ps1

@@ -24,8 +24,11 @@ Function Get-TypeParameterContent {
 
   ForEach ($Parameter in $ParameterInfo) {
     if (![string]::IsNullOrEmpty($Parameter.name)) {
+      if ($Parameter.name -ne 'ensurable') {
+        $Parameter.name = "dsc_$($Parameter.name)"
+      }
       New-Object -TypeName System.String @"
-    dsc_$($Parameter.name): {
+    $($Parameter.name): {
       type: $(ConvertTo-PuppetRubyString -String ($Parameter.Type -split "`n" -join "`n            ")),
 $(
   If ([string]::IsNullOrEmpty($Parameter.Help)) {