Codespaces: necessary formatters not registered

[dtivel]

Two MessagePack formatters are not registered. This results in serialization/deserialization errors of those types.

• RemoteErrorFormatter: [VS OE] Merge feature branch into dev branch NuGet.Client#3797 unregistered it, probably the result of an incorrect merge conflict resolution.
• IInstalledAndTransitivePackagesFormatter: Enable recommender for PackageReference style projects PR2 NuGet.Client#3680 added the new formatter but did not register it.