[navigation] use add_onload instead of inline javascript href
This way our javascript code isn't thrown out by the html cleaner e.g. when
using the rql rest directive and a table view.
Closes #3501626
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html