PackageReference Cleaner

Cleans the following crazy NuGet package reference mess:

<ItemGroup>
  <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.1" Pack="false" />
  <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1">
    <PrivateAssets>all</PrivateAssets>
    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  </PackageReference>
  <PackageReference Include="NuGetizer" Version="1.0.1">
    <PrivateAssets>all</PrivateAssets>
    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  </PackageReference>
  <PackageReference Include="PolySharp" Version="1.12.1">
    <PrivateAssets>all</PrivateAssets>
    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  </PackageReference>
  <PackageReference Include="ThisAssembly.AssemblyInfo" Version="1.2.12">
    <PrivateAssets>all</PrivateAssets>
    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  </PackageReference>
  <PackageReference Include="ThisAssembly.Git" Version="1.2.12">
    <PrivateAssets>all</PrivateAssets>
    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  </PackageReference>
  <PackageReference Include="GitInfo" Version="3.0.5">
    <PrivateAssets>all</PrivateAssets>
    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  </PackageReference>
</ItemGroup>

Into this perfectly clean and 100% equivalent beauty:

<ItemGroup>
  <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.1" Pack="false" />
  <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="all" />
  <PackageReference Include="NuGetizer" Version="1.0.1" PrivateAssets="all" />
  <PackageReference Include="PackageReferenceCleaner" Version="1.0.0" PrivateAssets="all" />
  <PackageReference Include="PolySharp" Version="1.12.1" PrivateAssets="all" />
  <PackageReference Include="ThisAssembly.AssemblyInfo" Version="1.2.12" PrivateAssets="all" />
  <PackageReference Include="ThisAssembly.Git" Version="1.2.12" PrivateAssets="all" />
  <PackageReference Include="GitInfo" Version="3.0.5" PrivateAssets="all" />
</ItemGroup>

How it works

A diagnostic analyzer inspects the MSBuild project file looking for <PackageReference> with PrivateAssets=all (via inner element or attribute), removes all its child nodes and moves (if necessary) the PrivateAssets child element to an attribute.

This is done automatically whenever the analyzer runs, and nothing is saved unless a node was cleaned.