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
GetMember/SetMember/InvokeMember operations on a COM object will generate code to unwrap the COM object if it's wrapped in PSObject. Due to a loose restriction, if you have a string wrapped to a PSObject with an ETS member of the same name, then the string PSObject will be unwrapped too and the ETS member will be lost. The fix is to use a more restricted rule by checking if the base object is a COM object.