Use package_adder when assigning workspace package uids

Signed-off-by: Jono Yang <jyang@nexb.com>

Author: JonoYang

src/packagedcode/npm.py

@@ -276,7 +276,9 @@ def create_packages_from_workspaces(
             if npm_res.for_packages:
                 continue
 
-            npm_res.for_packages = workspace_package_uids
+            for package_uid in workspace_package_uids:
+                package_adder(package_uid, npm_res, codebase)
+
             npm_res.save(codebase)
 
     @classmethod