No common exchange type used for IProgress<T> #122241
Description
It seems that most folks that use this interface end up defining their own DTO for T. That makes it hard to share progress values across libraries. I'm not sure if we've ever had the request before but it seems like a gap in our surface are for either BCL, Diagnostics, or Extnsions. We have Logger abstractions that are sufficient for shared exchange types for tracing, but our progress abstraction seems incomplete.