Better Artifact defaults when using built-in

[AndyGerlicher]

No description provided.

[dfederm]

My preferred change would be to change:

<EnableArtifacts Condition="'$(UseArtifactsOutput)' == 'true'">false</EnableArtifacts>

To:

<EnableDefaultArtifacts Condition="'$(UseArtifactsOutput)' == 'true'">false</EnableDefaultArtifacts>

and I guess move it from Microsoft.Build.Artifacts.Common.props to Microsoft.Build.Artifacts.props.

The "artifacts output layout" really just redirects the default outputs to a repo-rooted location. It doesn't solve the problem of arbitrary copies. So IMO only the default artifacts should be disabled, ie the implicit <Artifact Include="$(OutputPath)" DestinationFolder="$(ArtifactsPath)" />. Any explicit Artifact or Robocopy items should still be respected.