Update typed resgen to opt-in only

This makes it more predictable and explicit, also avoids generating strongly-typed resource classes for locales (which don't need them).

Author: kzu

src/Directory.Build.targets

@@ -106,19 +106,17 @@
     <RepositoryBranch Condition="'$(RepositoryBranch)' == '' and '$(BUDDY_EXECUTION_BRANCH)' != ''">$(BUDDY_EXECUTION_BRANCH)</RepositoryBranch>
   </PropertyGroup>  
 
-  <PropertyGroup Condition="'$(EnableRexCodeGenerator)' == 'true'">
-    <!-- VSCode/Razor compatibility -->
-    <CoreCompileDependsOn>PrepareResources;$(CoreCompileDependsOn)</CoreCompileDependsOn>
+  <PropertyGroup>
+    <!-- Default to Just Works resources generation. See https://www.cazzulino.com/resources.html -->
+    <CoreCompileDependsOn>CoreResGen;$(CoreCompileDependsOn)</CoreCompileDependsOn>
   </PropertyGroup>
-  
+
   <ItemGroup>
     <!-- Consider the project out of date if any of these files changes -->
     <UpToDateCheck Include="@(None);@(Content);@(EmbeddedResource)" />
-    <!-- We'll typically use ThisAssembly.Strings instead of the built-in resource manager codegen -->
-    <EmbeddedResource Update="@(EmbeddedResource)"  Generator="" Condition="'$(EnableRexCodeGenerator)' != 'true'" />
-    <EmbeddedResource Update="@(EmbeddedResource)" Condition="'$(EnableRexCodeGenerator)' == 'true'">
+    <!-- Opt-in to typed resource generation by setting custom tool to MSBuild:Compile -->
+    <EmbeddedResource Update="@(EmbeddedResource -> WithMetadataValue('Generator', 'MSBuild:Compile'))" Type="Resx">
       <!-- Default to Just Works resources generation. See https://www.cazzulino.com/resources.html -->
-      <Generator>MSBuild:Compile</Generator>
       <StronglyTypedFileName>$(IntermediateOutputPath)\$([MSBuild]::ValueOrDefault('%(RelativeDir)', '').Replace('\', '.').Replace('/', '.'))%(Filename).g$(DefaultLanguageSourceExtension)</StronglyTypedFileName>
       <StronglyTypedLanguage>$(Language)</StronglyTypedLanguage>
       <StronglyTypedNamespace Condition="'%(RelativeDir)' == ''">$(RootNamespace)</StronglyTypedNamespace>