format: read metadata from object not result

Now that metadata is stored and can be accessed via `Object.meta`,
read it from the built or stored objects when serializing the
result in the `format.output` functions.

osbuild/main_cli.py

@@ -169,7 +169,7 @@ def osbuild_cli():
                     export(pid, output_directory, object_store, manifest)
 
             if args.json:
-                r = fmt.output(manifest, r)
+                r = fmt.output(manifest, r, object_store)
                 json.dump(r, sys.stdout)
                 sys.stdout.write("\n")
             else: