[FIX] website_links: fix multiple bugs + add tests

Commit 6d67ce5b refactored the JS from multiple website modules including
`website_links`.
A few error needed to be fixed:
  - recent links would not appear anymore
  - graphs would not be displayed anymore
  - graph resize on tab change would not be fired

This commit fixes it and also add some tests to be sure this module is now
strongly tested.

Note: tests are skipped for now as there is a race condition happening only
      with docker and this fix is getting urgent for Odoo.com

closes odoo/odoo#31507

Signed-off-by: Romain Derie (rde) <rde@odoo.com>