show fullscreen bubble view of ranking (with d3.js)

use d3.js to show a bubble view, like on previous version

example:

https://observablehq.com/@d3/bubble-chart

First draft:

a83c3783

still missing:

• comments and documentation (I don't even know how it works)
• report.subject.name is hardcoded ! https://gitlab.cylab.be/cylab/mark-web/-/blob/a83c37837b5395e41dfaa8ba522e06237ea886df/resources/views/app/bubble.blade.php#L52
• responsive design (width and height are hardcoded) https://gitlab.cylab.be/cylab/mark-web/-/blob/a83c37837b5395e41dfaa8ba522e06237ea886df/resources/views/app/bubble.blade.php#L5
• automatic / dynamic update
• limit to first 100 (?) subjects, to avoid overloading the screen!

mentioned in commit a413d428

58d0c0f9 b25c6074

1b16dbce