draft: hack together arbitrary container layer support for SDK Containers

[baronfel]

Putting this up as a checkpoint - this works now.

Add

	<ItemGroup Condition="$(RuntimeIdentifier) == 'linux-x64'">
		<ContainerAdditionalLayer Include="sha256:5d07f997927bfbc756cee47f7bb55825a1315fae3d1d9697411b3fe478058ddf" 
			Registry="docker.io" 
			Repository="appdynamics/dotnet-core-agent"
			MediaType="application/vnd.docker.image.rootfs.diff.tar.gzip"
			Size="13558922" />
	</ItemGroup>
	<ItemGroup Condition="$(RuntimeIdentifier) == 'linux-arm64'">
		<ContainerAdditionalLayer Include="sha256:6b24f8c3a780589d68e6f09b3b45dcb499b446db54727d89b73ea5e4e1d081eb" 
		Registry="docker.io" 
		Repository="appdynamics/dotnet-core-agent"
		MediaType="application/vnd.docker.image.rootfs.diff.tar.gzip"
		Size="13576182" />
	</ItemGroup>

to a project file and publish for various RIDs to see it working.