Add YARP images to official repo

This issue tracks moving the [YARP images](https://mcr.microsoft.com/en-us/artifact/mar/dotnet/nightly/yarp/about) (currently in the nightly repo only) to the official repo, `mcr.microsoft.com/dotnet/yarp`. This should be done when the YARP images are considered "finished"/stable, and have a clear support policy and lifecycle.