Improve license check output

Closes: gitlab-org/distribution/team-tasks#214 (closed)

Sample output:

1. Package page - https://code.balasankarc.in/license/gitlab-ce/11.4/11.4.3-ce.0.html
2. Index page - https://code.balasankarc.in/license/licenses.html

What this MR does

1. Generate a JSON file of the dependency license information (including level-1 deps).
2. Improve the webpages
   1. Move to a single index page to list both CE and EE packages
   2. Better looking webpage for each page. level-0 deps with collapsible divs for level-1 deps
3. Refactor the pipeline
   1. Webpage generation for each package and upload to S3 bucket happens in release pipeline
   2. Pulling down the S3 bucket, generating index page from available license files and generating assets for GL pages happen in .com pipeline (scheduled)