Content-side changes for packaging. (#9382)

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Packaging/ContentPackaging.cs

@@ -0,0 +1,32 @@
+using Robust.Packaging;
+using Robust.Packaging.AssetProcessing;
+
+namespace Content.Packaging;
+
+public static class ContentPackaging
+{
+    public static async Task WriteResources(
+        string contentDir,
+        AssetPass pass,
+        IPackageLogger logger,
+        CancellationToken cancel)
+    {
+        var graph = new RobustClientAssetGraph();
+        pass.Dependencies.Add(new AssetPassDependency(graph.Output.Name));
+
+        AssetGraph.CalculateGraph(graph.AllPasses.Append(pass).ToArray(), logger);
+
+        var inputPass = graph.Input;
+
+        await RobustClientPackaging.WriteContentAssemblies(
+            inputPass,
+            contentDir,
+            "Content.Client",
+            new[] { "Content.Client", "Content.Shared", "Content.Shared.Database" },
+            cancel);
+
+        await RobustClientPackaging.WriteClientResources(contentDir, inputPass, cancel);
+
+        inputPass.InjectFinished();
+    }
+}