Prepare repo to build 2.2.1

* Update dependencies to 2.2.0 rtm
* Update branding to 2.2.1
* Update package baselines to 2.2.0
* Add a restore source for 2.2.0 RTM
\n\nCommit migrated from 913f74d590

src/Testing/src/Microsoft.AspNetCore.Testing.csproj

@@ -8,6 +8,8 @@
     <PackageTags>aspnetcore</PackageTags>
     <EnableApiCheck>false</EnableApiCheck>
     <IsPackable>true</IsPackable>
+    <!-- This package is internal, so we don't generate a package baseline. Always build against the latest dependencies. -->
+    <UseLatestPackageReferences>true</UseLatestPackageReferences>
   </PropertyGroup>
 
   <ItemGroup>