Add a function for checking NuGet packages

scripts/Windows/Scripts/SoftwareManagement.ps1

@@ -56,3 +56,18 @@ function Test-Command {
 
     [bool] (Get-Command $Name -ErrorAction SilentlyContinue);
 }
+
+<#
+    .SYNOPSIS
+    Checks whether a package with the specified name is installed.
+
+    .PARAMETER Name
+    The name of the package to check.
+#>
+function Test-PSPackage {
+    param(
+        [string] $Name
+    )
+
+    [bool] (Get-Package $Name -ErrorAction SilentlyContinue);
+}