Detecting licenses declared in LICENSE file and LICENSES folder

[NicolasToussaint]

Description

As discussed in Issue #1592, and to improve adoption of REUSE (https://reuse.software/) standards, Fossology could detect and display the licenses included in the LICENSE file, as well as licenses found in the LICENSES folder, both located in root folder.

The goal here is to process and report these license texts a bit differently compared to license texts found in other places in the source code. That will help verifying that the license texts are properly declared.

Steps followed and expected result

Rough idea, to be challenged :-)

1. When clearing a file, specifically add an attribute to a license (Declared license ?)
   It could be a new icon next to the "Main License" yellow star, or a new column in this table:
   
2. When displaying the licenses lists, add a table recapping the "Declared" licenses, above Summary:
   

Not sure if it should and how it could be used in the reports though.

[NicolasToussaint]

Notes after discussion:

• Every file in the LICENSES folder will be considered as a Declared License automatically, once it has been cleared.
• The feature can be [de]activated via a new option in the Conf page (for each Upload) ; Feature activated by default for all new Uploads.
• Add a new table in the Summary section of the Upload

To do next:

• For every Declared License, find a way to show in the UI