Jest setTimeout in tests

@NicolasGlassey

After our discussion about `jest.setTimeout(10000);`, here is the stackoverflow thread that lead us to implement jest this way :

https://stackoverflow.com/questions/49603939/message-async-callback-was-not-invoked-within-the-5000-ms-timeout-specified-by

The issue only mentions Jest's setTimeout(10000) usage and a Stack Overflow discussion; start by locating that test configuration in the repository. The desired change and completion criteria are not stated, so clarify whether the timeout should be retained, changed, or documented before editing.

Written by the indexing model from the issue text.