Update copyright and license headers (#6134)

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

docker/tests/container.tests.ps1

@@ -1,3 +1,6 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 Import-module -Name "$PSScriptRoot\containerTestCommon.psm1" -Force
 $script:linuxContainerTests = Get-LinuxContainer
 $script:windowsContainerTests = Get-WindowsContainer

docker/tests/containerTestCommon.psm1

@@ -1,3 +1,6 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 $script:forcePull = $true
 # Get docker Engine OS
 function Get-DockerEngineOs
@@ -87,7 +90,6 @@ function Get-WindowsContainer
     }
 }
 
-
 $script:repoName = 'microsoft/powershell'
 function Get-RepoName
 {
@@ -251,7 +253,6 @@ function Test-PSPackage
     $packageLocationStubName = 'PACKAGELOCATIONSTUB'
     $packageLocationStubValue = $PSPackageLocation
 
-
     $results = @{}
     $returnValue = $true