After renaming a variant, wrong task name

[flomnes]

How to reproduce

1. Create a variant study
2. Rename the variant
3. Launch the study
4. The task associated to this launch has the former name of the variant, it should have the updated name

[makdeuneuv]

Behavior observed: On Antares Web, the tasks of the simulations have the name of the associated study, the same applies to the variants. After renaming a variant and launching a study immediately after, the task associated with the launch have the previous name of the variant.

1. Screenshot creation variant
2. Launch simulation, the task have the name of the variant
3. Renaming the variant
4. Launching simulation, the task have the previous name

expected behavior: When a variant is renamed, the tasks of future launched simulations must have its new name.