Measure-Object should handle `ScriptBlock` properties. Fixed by renaming `MshExpression` to `PSPropertyExpression` and making it public. Then in `MeasureObjectCommand`, lifting it up to the parameter level. Previously the implementation exposed the Property as a string and
wrapped it internally as a `PSPropertyExpression`. Now the parameter type is `PSPropertyExpression` directly allowing for both wildcard strings and `ScriptBlock`.
`PSPropertyExpression` now lives in a public namespace where it can be used by cmdlet and script authors to easily add the same type of functionality to their commands. I also modified `PSPropertyExpression` to handle hashtables properly as objects so
@{prop = 3} | measure-object prop
and
@{prop = 3} | measure-object {$_.prop}
will work the same. (Previously the example using just the property name would fail.)
Based on standard practices, we need to have a copyright and license notice at the top of each source file. Removed existing copyrights and updated/added copyright notices for .h, .cpp, .cs, .ps1, and .psm1 files.
Updated module manifests for consistency to have Author = "PowerShell" and Company = "Microsoft Corporation". Removed multiple line breaks.
Separate PR coming to update contribution document for new source files: #6140
Manually reviewed each change.
Fix#6073
Ilya