Charts UI: charts export and copy commands are sometimes not displayed

NOTE AL from #4032 (closed): L'entrée "Exporter le graphique" dans le menu du graphique AFC n'apparait pas tout de suite : il faut cliquer sur le bouton exporter d'abord (sinon seules les commandes "exporter les données" et "copier les données..." sont visibles :

The export menu is filled using the active editor result. But when opening the CA editor export menu the CA editor is not reactivated and the export menu is not correctly filled

To reproduce

1. Compute a CA
2. select a line of one of the CA infos window
3. open the export choices with the "v" button (without touching another part of the CA window)
4. bug only 2 are available (the active editor window is not the CA window)