Continued refactor, minor cleanup, fixed WASM head

Author: Arlodotexe

MultiTarget/Library.props

@@ -9,13 +9,13 @@
   <Import Project="$(ToolingDirectory)\MultiTarget\EnabledMultiTargets.props" />
   <Import Project="$(ToolingDirectory)\MultiTarget\EnabledTargetFrameworks.props" />
 
+  <!-- Use <MultiTarget> values to define <TargetFrameworks> -->
+  <Import Project="$(ToolingDirectory)\MultiTarget\MultiTargetToTargetFramework.props" />
+
   <!-- Enable project identifiers -->
   <Import Project="$(ToolingDirectory)\MultiTarget\ProjectIdentifiers.props" />
   <Import Project="$(ToolingDirectory)\MultiTarget\DefinedConstants.props" />
 
-  <!-- Use <MultiTarget> values to define <TargetFrameworks> -->
-  <Import Project="$(ToolingDirectory)\MultiTarget\MultiTargetToTargetFramework.props" />
-
   <!-- Add platform package dependencies -->
   <Import Project="$(ToolingDirectory)\MultiTarget\PackageReferences\Netstandard.props" Condition="$(IsNetstandard) == 'true'" />
   <Import Project="$(ToolingDirectory)\MultiTarget\PackageReferences\Uno.props" Condition="$(IsUno) == 'true'" />

MultiTarget/PackageReferences/Netstandard.props

@@ -1,5 +1,5 @@
 <Project>
   <ItemGroup>
-        <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
+    <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
   </ItemGroup>
 </Project>

MultiTarget/PackageReferences/Uno.props

@@ -29,8 +29,4 @@
     <ItemGroup Condition="'$(IsWasmHead)' == 'true'">
         <PackageReference Include="Uno.UI.WebAssembly" Version="4.6.18" />
     </ItemGroup>
-
-    <ItemGroup>
-        <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
-    </ItemGroup>
 </Project>

MultiTarget/PackageReferences/Windows.props

@@ -1,6 +1,7 @@
 <Project>
   <ItemGroup Condition="'$(IsUwp)' == 'true'">
     <PackageReference Include="Microsoft.UI.Xaml" Version="2.7.0" />
+    <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsWinAppSdk)' == 'true'">

ProjectHeads/App.Head.Uno.props

@@ -1,6 +1,7 @@
 <Project>
     <Import Project="$(MSBuildThisFileDirectory)\App.Head.props" />
     <Import Project="$(MSBuildThisFileDirectory)\..\MultiTarget\PackageReferences\Uno.props" />
+    <Import Project="$(MSBuildThisFileDirectory)\..\MultiTarget\WinUI.Extra.props" />
 
     <!--
         Import Uno dependencies for all deployable Uno-based Labs project heads.

ProjectHeads/Head.Uwp.props

@@ -121,9 +121,6 @@
         <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
             <Version>6.2.12</Version>
         </PackageReference>
-        <PackageReference Include="Microsoft.UI.Xaml">
-            <Version>2.7.0</Version>
-        </PackageReference>
     </ItemGroup>
 
     <PropertyGroup Condition=" '$(VisualStudioVersion)' == '' or '$(VisualStudioVersion)' &lt; '14.0' ">