Add support for showing license clues

[pombredanne]

I scan https://files.pythonhosted.org/packages/50/d3/d346f779cbc9384d8b805a7557b5f2b8ee9f842bffebec9fc6364d6ae183/pylint-3.2.3-py3-none-any.wh with scan_single package
ScanCode.io_ 3fa2a1f68d.f95201a764.ce71b4612d.pdf
The summary shows " mit OR gpl-2.0 " as an "other license" but I cannot find it anywhere

[tdruez]

The "Scan summary" panel displays data from the summary generated by ScanCode-toolkit using the --summary option.

Unfortunatly, the summary data as provided by the toolkit does not offer more context about the detection:

summary": {
    "declared_license_expression": "gpl-2.0 AND gpl-2.0-plus",
    "other_license_expressions": [
      {
        "value": "gpl-2.0-plus",
        "count": 162
      },
      {
        "value": "gpl-2.0",
        "count": 27
      },
      {
        "value": null,
        "count": 7
      },
      {
        "value": "mit OR gpl-2.0",
        "count": 7
      },
...

I believe PR #1124 is about providing much more information in the UI about the license detection and should make license data investigation much easier.

@AyanSinhaMahapatra could you confirm the pertinence of #1124 in this ghost license context? Also, what's the status there, any blockers?

[AyanSinhaMahapatra]

This is now fixed at #1124

These were license clues which needed to be stored and showed correctly.

Now the summary license-expressions also have a link to the corresponding license detections:

The license clues can also be looked at via a link in the license detection summary panel:

The PR is almost ready, 2 things remaining:

1. Highlight license issues
2. Add a couple more tests and a CHANGELOG entry