Fix win_domain_computer

Fixes #43653

- Change descrtiption parameter default to null.
  When reading an empty description from AD, powershell returns a null.
- Convert after and before diff keys to ordered hashes.
  Unordered state descriptions make --diff report equal values as
  changes.

lib/ansible/modules/windows/win_domain_computer.ps1

@@ -25,14 +25,14 @@ If (-not $sam_account_name.EndsWith("$")) {
   Fail-Json -obj $result -message "sam_account_name must end in $"
 }
 $enabled = Get-AnsibleParam -obj $params -name "enabled" -type "bool" -default $true
-$description = Get-AnsibleParam -obj $params -name "description" -default ""
+$description = Get-AnsibleParam -obj $params -name "description" -default $null
 $state = Get-AnsibleParam -obj $params -name "state" -ValidateSet "present","absent" -default "present"
 If ($state -eq "present") {
   $dns_hostname = Get-AnsibleParam -obj $params -name "dns_hostname" -failifempty $true -resultobj $result
   $ou = Get-AnsibleParam -obj $params -name "ou" -failifempty $true -resultobj $result
   $distinguished_name = "CN=$name,$ou"
 
-  $desired_state = @{
+  $desired_state = [ordered]@{
     name = $name
     sam_account_name = $sam_account_name
     dns_hostname = $dns_hostname
@@ -43,7 +43,7 @@ If ($state -eq "present") {
     state = $state
   }
 } Else {
-  $desired_state = @{
+  $desired_state = [ordered]@{
     name = $name
     state = $state
   }
@@ -58,7 +58,7 @@ Function Get-InitialState($desired_state) {
       -Properties DistinguishedName,DNSHostName,Enabled,Name,SamAccountName,Description,ObjectClass
   } Catch { $null }
   If ($computer) {
-      $initial_state = @{
+      $initial_state = [ordered]@{
         name = $computer.Name
         sam_account_name = $computer.SamAccountName
         dns_hostname = $computer.DNSHostName
@@ -70,7 +70,7 @@ Function Get-InitialState($desired_state) {
         state = "present"
       }
   } Else {
-    $initial_state = @{
+    $initial_state = [ordered]@{
       name = $desired_state.name
       state = "absent"
     }