Meta Issue: File classification and categorization

We have several issues related to categorization and classification. This is a meta issue to track the latest and refactor these in roadmap entries. In general, the actual classification and categorization should be best handled in ScanCode Toolkit. Applying these to automate scan processing would be best in ScanCode.io.

- https://github.com/nexB/scancode-toolkit/issues/377
- https://github.com/nexB/scancode-toolkit/issues/426
- https://github.com/nexB/scancode-toolkit/issues/1012
- https://github.com/nexB/scancode-toolkit/issues/1036
- https://github.com/nexB/scancode-toolkit/issues/1445
- https://github.com/nexB/scancode-toolkit/issues/1745
- https://github.com/nexB/scancode-toolkit/issues/1754
- https://github.com/nexB/scancode-toolkit/issues/2945
- https://github.com/nexB/scancode-toolkit/issues/3282

And one PR:
- https://github.com/nexB/scancode-toolkit/pull/2958