bpo-34977: Add Windows App Store package (GH-11027)

Also adds the PC/layout script for generating layouts on Windows.
diff --git a/PCbuild/python_uwp.vcxproj b/PCbuild/python_uwp.vcxproj
new file mode 100644
index 0000000..af187dd
--- /dev/null
+++ b/PCbuild/python_uwp.vcxproj
@@ -0,0 +1,86 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="PGInstrument|Win32">
+      <Configuration>PGInstrument</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="PGInstrument|x64">
+      <Configuration>PGInstrument</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="PGUpdate|Win32">
+      <Configuration>PGUpdate</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="PGUpdate|x64">
+      <Configuration>PGUpdate</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{9DE9E23D-C8D4-4817-92A9-920A8B1FE5FF}</ProjectGuid>
+  </PropertyGroup>
+  <Import Project="python.props" />
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseOfMfc>false</UseOfMfc>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="pyproject.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup>
+    <_ProjectFileVersion>10.0.30319.1</_ProjectFileVersion>
+  </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <PreprocessorDefinitions>%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/EHsc /std:c++17 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <AdditionalDependencies>windowsapp.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <None Include="..\PC\pycon.ico" />
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="..\PC\python_exe.rc" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\PC\python_uwp.cpp" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="pythoncore.vcxproj">
+      <Project>{cf7ac3d1-e2df-41d2-bea6-1e2556cdea26}</Project>
+      <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>