Copy signed assemblies to the localize artifacts folder

[donnie-msft]

Bug

Fixes: https://github.com/NuGet/Client.Engineering/issues/3024

Description

• Localization no longer copies NuGet assemblies to the output directory.
• A new build step runs after localization and signing completes: Copy signed assemblies to localize artifacts folder
• The build step runs an MSBuild target which copies the signed assemblies from artifacts\ to artifacts\localizationArtifacts\artifacts as shown in this binlog snippet:
  

Validation of signed loc files:

Before this PR

Checking artifacts shows a test-signed assembly.

 sn -vf C:\users\____\Downloads\localizationArtifacts\localizationArtifacts\artifacts\NuGet.Credentials\bin\release\net8.0\NuGet.Credentials.dll

C:\users\____\Downloads\localizationArtifacts\localizationArtifacts\artifacts\NuGet.Credentials\bin\release\net8.0\NuGet.Credentials.dll is a delay-signed or test-signed assembly

After this PR

Checking artifacts shows a valid, signed assembly.

sn -vf C:\users\____\Downloads\Signed_localizationArtifacts\localizationArtifacts\artifacts\NuGet.Credentials\bin\release\net8.0\NuGet.Credentials.dll

Microsoft (R) .NET Framework Strong Name Utility  Version 4.0.30319.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Assembly 'C:\users\____\Downloads\Signed_localizationArtifacts\localizationArtifacts\artifacts\NuGet.Credentials\bin\release\net8.0\NuGet.Credentials.dll' is valid

They are also Authenticode signed

PR Checklist

• Meaningful title, helpful description and a linked NuGet/Home issue
• Added tests - Checked artifacts on a build and reviewed binlog.
• Link to an issue or pull request to update docs if this PR changes settings, environment variables, new feature, etc. Localized artifacts now contain Authenticode signed assemblies #6172

[jeffkl]

🕺