Manage the linked editors grouping/boxing

WIP

EG : the CA editor and its linked editors

This issue is linked to the question of results that can have more than one editor synchronously linked to them and what is the better way to show that in the UI, eg. Progression <=> Concordance, Progression <=> Edition or more generally a kind of container “box” that shows to the user which editors compose a focus of an analysis.

Solution

create some kind of “Analysis/Focus box”

(from redmine: issue id 2405, created on 2018/06/11 by Sebastien Jacquot)