* display CommandParsing gracefully
This set of changes handles CommandParsingException gracefuly (so as not to show the user a stack trace) and generalizes graceful exception display somewhat away from being type-specific.
* fix compile error by inlining constant
* remove unused test logging
Also removed the dependency on Microsoft.Extensions.CommandLineUtils.Sources NuGet package and instead just checking the source files into our repo as internal classes.
Fix#2526