[Feature Request] Simplify platform configurations

[julealgon]

I'd like to propose a simpler configuration setup, where when a single platform is defined, it would automatically apply to every single project without having to explicitly specify the platform on a per-project basis.

We converted our ~170 project solution to slnx and it resulted in a structure like this:

<Solution>
  <Configurations>
    <Platform Name="x64" />
  </Configurations>
  <Project Path="Project1.csproj">
    <Platform Project="x64" />
  </Project>
  <Project Path="Project2.csproj">
    <Platform Project="x64" />
  </Project>
  <Project Path="Project3.csproj">
    <Platform Project="x64" />
  </Project>

  ...

  <Project Path="Project170.csproj">
    <Platform Project="x64" />
  </Project>
</Solution>

As you can see, the added <Platform node adds a ton of noise and redundancy. Effectively, it triples the overall line count of the file.

I'd love to have something like this instead:

<Solution>
  <Configurations>
    <Platform Name="x64" />
  </Configurations>
  <Project Path="Project1.csproj" />
  <Project Path="Project2.csproj" />
  <Project Path="Project3.csproj" />

  ...

  <Project Path="Project170.csproj" />
</Solution>

Literally every single project in our solution is configured the same way, as the settings are defined in a Directory.Build.props file like this:

<Project>

 <PropertyGroup>
   <ImplicitUsings>enable</ImplicitUsings>
   <Platforms>x64</Platforms>
   <PlatformTarget>x64</PlatformTarget>
   <AppendPlatformToOutputPath>false</AppendPlatformToOutputPath>
   <RuntimeIdentifier>win-x64</RuntimeIdentifier>
   <AppendRuntimeIdentifierToOutputPath>false</AppendRuntimeIdentifierToOutputPath>
 </PropertyGroup>

</Project>

The added verbosity on our slnx file defeats some of the purpose of moving into the new format.

I actually tried removing those nodes just to see what would happen, but then the projects stop building in Visual Studio and I get a warning at the top when the solution loads saying that "the configurations are wrong"

Interestingly enough, opening the configuration manager doesn't do anything in this case.