Create error reporting output

[KathleenDollard]

This will be a good first issue for someone who has some understanding of System.CommandLine and wants to understand how the new pipeline design works. It involves finding the error reporting code in System.CommandLine extended (in main-powderhouse branch and putting it in ErrorReportingSubsystem.Execute

This part is very easy. However, testing will require resolution of #2345.

If you do not want to wait, consider:

• Use an internal method in ErrorReportingSubsystem that takes a collection to avoid the ReadonlyList on ParseResult
• Copy 'ParseError' to the System.CommandLine.Subsystem (I think that gives it precedence) or copy it and give it a recognizable fake name like ParseError2
• Do a draft PR because we can't take this as is. The draft PR will ensure we move the decision in Replace ParseError/string errors with Error and use generally #2345 to the front of the queue of things to resolve

[JeanJoeris]

Taking a look at this, will put up a draft PR, but it sounds like #2345 is leaning towards ParseError being public so I'll write with that in mind

[karshav16]

Would love to contribute!