Improve presentation of the project details section: "Resources detected license expressions"

[pombredanne]

On the project details page, I would like an improved presentation of the "Resources detected license expressions" section:

• Rename this to something shorter like "Top Detected licenses in files"
• Order the list by the number of detections, higher first
• Do not put "not licenses" at the top, because this number depends on whether the pipeline ran a license detection or not, keep it at the bottom of the list.
• Possibly limit the list length to about 10 top or 20 top license expressions

[tdruez]

All the suggestions were implemented in #964

Keeping this open as we could add a link at the bottom of this panel to the "grouped by" view, once implemented in #950, to redirect to the list grouped by licenses.