Fix project build error after installing Fody NuGet package.

The Fody NuGet package has an install PowerShell script that
directly updates the MSBuild project from the
Microsoft.Build.Evaluation.ProjectCollection.GlobalProjectCollection
to set a FodyPath property that defines where the Fody.targets
file should find the main Fody assembly.

Extended the support added for the Microsoft.Bcl.Build NuGet package
so project properties added by directly updating the MSBuild project
from the GlobalProjectCollection are added/updated in the actual
project file.

No support for updating properties that exist multiple times inside
a project (e.g. OutputPath).