cubicweb-relationwidget #4369292 js crash when using linkto to preselect entities [open]

To reproduce:

  • preselect a linked entity for the relation you edit with the relationwidget; the entity appears with a checked checkbox; note it is not a link, but a plain text label
  • open the widget, click on a facet
  • a crash occurs, leading to line selected[eid] = $('a', $this)[0].outerHTML; (after some digging)

The reason for this is we try to display links for selected entities all the way long, but forgot the linkto case in RelationFacetWidget._render_triggers

done in<not specified>
load left0.250
closed by<not specified>