Add examples / samples back to solution

[nohwnd]

In #2340 I removed samples from the main solution because they were using the versions from the test assets which would prevent the build from finishing, because test assets now build against the results of the main build. I don't think samples should use our complicated build, and instead should pin normal versions from nuget. Add them back in the same solution or in separate solution that will be built on the CI but won't fail the build. Samples are not supposed to be acceptance tests.