Try the parallelisation of the RunModel_DA function

It could be nice to add the possibility to run in a parallel way the runs of the ensembles. However, we would need a dependence to an external package. In addition, would it really be efficient, as the loading of the objects could slow down the app?

In practice, all runModels would require the same time to run.

Maybe the current acceleration proposed by Olivier is enough...

Gaia, what is parallelized in the PF and EnKF in Matlab?