Sync publish workflow with upstream oss

Remove current implementation of SponsorLink for now

Now that SponsorLink is OSS and based on received feedback
it will change in many ways moving forward, we'll for now
remove the current implementation from the package to address
the issues that were raised.

See https://github.com/devlooped/SponsorLink

Cleanup package description

Remove Common from Mvp.Xml namespaces

No need for the additional Common everywhere.

Fix publish step to nuget.org