Consider not adding trailing '/' to directory paths when generating CSV from JSON output

While trying to match file/directory paths from one CSV to another, I've encountered challenges when some paths do, and others do not, include a trailing `/`.

I've examined the latest `develop` branch and it seems that while the JSON output of scancode-toolkit does not have a trailing `/` for directories, the CSV generated by scancode-toolkit (as part of a scan or via `--from-json`) adds a trailing `/` to each directory path. (I've downloaded/installed scancode-toolkit-21.2.25 on WSL2 but not yet had time to test the `/` in the CSVs.)

I don't think this is a bug -- it was probably incorporated for a specific purpose at some point -- but unless it's a breaking change of some sort, it would be helpful to remove that functionality from the CSV-generation process.