Have the ability to delete several functionalities at the same time

**What it's the actual situation on ARA ?**
Currently, on ARA, the multiple deletions of functionalities don't work, it must therefore be done one by one what can be time-consuming as a task.

Actually, we can select more than one functionalities but when I click on the delete button, just one functionality is taken into account

**Describe the solution you'd like**
What I would like, would be to have the possibility to select several functionalities at the same time and thus proceed to the deletion in one shot.

Start by reproducing the issue in ARA: select several functionalities and click the delete button. Trace the deletion flow to determine why only one selected functionality is handled. Done means all selected functionalities are deleted in one operation while the existing single-deletion behavior still works.

Written by the indexing model from the issue text.