Move UAC handling to context

scripts/Windows/Scripts/Context.ps1

@@ -148,6 +148,11 @@ class Context {
         $action.Invoke($key);
     }
 
+    [Microsoft.Win32.RegistryKey] GetSystemPolicyKey() {
+        $keyPath = "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System";
+        return Get-Item "$keyPath";
+    }
+
     [Microsoft.Win32.RegistryKey] GetRunOnceKey() {
         return $this.GetRunOnceKey($null);
     }
@@ -169,6 +174,14 @@ class Context {
         return $result;
     }
 
+    [bool] GetUACState() {
+        return [bool](Get-ItemPropertyValue -Path ($this.GetSystemPolicyKey().PSPath) -Name "EnableLUA");
+    }
+
+    [void] SetUACState([bool] $value) {
+        $null = Set-ItemProperty -Path ($this.GetSystemPolicyKey().PSPath) -Name "EnableLUA" -Value [int]$value;
+    }
+
     [void] RegisterReboot() {
         $this.RegisterReboot($null);
     }