Scancode output doesn't populate correct files.for_packages values

### Description

I've got a js project called omni, that I've pulled my deps into node_modules and the values for all the `files.for_pacakges` is "pkg:npm/omni?uuid=b37e5fd3-599d-4287-a8e3-fd04ce2aa0d0", instead of the values I'd expect that match the values in `dependencies`.

### How To Reproduce

The project I'm working on is proprietary. Do you have any open/public js test projects that you commonly use for testing that I can try to reproduce this with?

### System configuration

* What OS are you running on? (Windows/MacOS/Linux): MacOS
* What version of scancode-toolkit was used to generate the scan file?
** ScanCode version: 31.1.1
** ScanCode Output Format version: 2.0.0
** SPDX License list version: 3.17
* What installation method was used to install/run scancode? (pip/source download/other): from source