Enabling XLIFF generation (#172)

* Add xliff generation for localization that doesn't depend on IsShipping being true.

* Adding System.Xaml xliff files

src/Microsoft.DotNet.Wpf/src/Directory.Build.Props

@@ -7,4 +7,11 @@
     <WpfSharedDir>$(MSBuildThisFileDirectory)Shared\</WpfSharedDir>
     <WpfCommonDir>$(MSBuildThisFileDirectory)Common\</WpfCommonDir>
   </PropertyGroup>
+
+  <!-- Localization -->
+  <PropertyGroup>
+    <EnableXlfLocalization>true</EnableXlfLocalization>
+  </PropertyGroup>
+
+  <Import Project="Localization.targets"/>
 </Project>

src/Microsoft.DotNet.Wpf/src/Localization.targets

+<?xml version="1.0" encoding="utf-8"?>
+<!-- All Rights Reserved. Licensed to the .NET Foundation under one or more agreements. The .NET Foundation licenses this file to you under the MIT license. See the LICENSE file in the project root for more information. -->
+<Project>
+
+  <!--
+    When not building in CI, automatically sync .xlf files to .resx files on build.
+    Otherwise, let the build fail to catch .xlf files that are not up-to-date.
+  -->
+
+  <PropertyGroup>
+    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <!-- 
+      It is only intended to automatically run update during dev cycle. However, it will fail the build on CI if the XLF file is not updated.
+      XLF file should be checked in and loc team will update the XLF it with translated version.
+    -->
+    <UpdateXlfOnBuild Condition="'$(ContinuousIntegrationBuild)' != 'true'">true</UpdateXlfOnBuild>
+
+    <!--
+      Use Satellite assembly generation task from Microsoft.NET.Sdk even when building with
+      full Framework MSBuild. This will support public signing, is deterministic, and always
+      generates them as AnyCPU. 
+    -->
+    <GenerateSatelliteAssembliesForCore Condition="'$(GenerateSatelliteAssembliesForCore)' == ''">true</GenerateSatelliteAssembliesForCore>
+  </PropertyGroup>
+
+  <ItemGroup>
+     <!-- 
+        Arcade localization targets require that IsShipping is set to true.  We import the XliffTasks explicitly since
+        we would like to localize our resources without having to depend on IsShipping.
+        TODO: If Arcade takes a change in the future, we can remove this from the build.
+    -->
+    <PackageReference Include="XliffTasks" Version="$(XliffTasksVersion)" PrivateAssets="all" IsImplicitlyDefined="true"/>
+  </ItemGroup>
+</Project>
\ No newline at end of file