Fix malakoff assembly edit

[Stef-Rousset]

🎩 Description

This PR overrides the FindAndUpdateDescendantsJob to improve its speed execution and avoid timeout when updating, publishing/unpublishing a participatory space.
Override by @AyakorK, and tests by myself.

Testing

1. As an admin, go to a published assembly with components and unpublish it
2. See that the unpublishing action takes around 10 seconds (40 seconds before improvment)
3. In the FO, go to the search bar, and search for a child of the assembly, for instance search a meeting by its title
4. See that the meeting is not found (proving that the job has been correctly executed)
5. Go to the BO again and publish the assembly
6. Repeat step 3 and see that you find the meeting
7. Go to the BO again and update the assembly
8. Repeat step 6

📌 Related Issues

• Fixes https://github.com/orgs/OpenSourcePolitics/projects/26/views/1?pane=issue&itemId=132239776&issue=OpenSourcePolitics%7Cintern-tasks%7C136

Tasks

• Add specs

📷 Screenshots

Please add screenshots of the changes you're proposing if related to the UI

[BarbaraOliveira13]

Works as expected locally 🎉

Great job! Maybe add a test with a “big” assembly: for example, one containing 5 components, each with ~200 proposals, and each proposal having ~10 comments...
What do you think? @Stef-Rousset @moustachu ?

Instead LGTM !

[Bertille-M]

@Stef-Rousset Is there any thing else to do on this PR ?