Here is the list of SharePoint specific MSBuild properties and there is nothing about package name. So you have to use workaround for that e.g.
First you get lists of package files and pdb files like that:
<ItemGroup>
<PackageFiles Include="$(BasePackagePath)\*.$(PackageExtension)" />
<PdbFiles Include="$(BasePackagePath)\*.pdb)" />
</ItemGroup>
And then you can use it in regular copy command.
I didn't test it but it should work.