Squashed commit of the following:

commit a861c34b
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Tue Mar 19 17:11:51 2024 +0100

    Refactorisation : use of write_mercator_multi.m
    instead of write_mercator_frcst.m

commit 747149f7
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Tue Mar 19 15:18:50 2024 +0100

    Cleaning

commit 0dc67715
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Tue Mar 19 14:29:18 2024 +0100

    Update in download_mercator_frcst_python

commit f5c9aadd
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Mon Mar 18 14:33:52 2024 +0100

    Cleaning in make_OGCM_frcst
        - Rename make_OGCM_frcst.m  in make_OGCM_mercator_frcst.m
        - some simplifications

commit 90a6ebc1
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Mon Mar 18 14:20:30 2024 +0100

    Remove ECCO product from Forecast_tools

commit 5040ce6c
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Mon Mar 18 14:17:33 2024 +0100

    Remove original file "raw_mercator_name" after download

commit a1fae6b9
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Mon Mar 18 14:11:52 2024 +0100

    Remove downloading of taux/tauy in extract_SODA

commit 76fc422b
Author: Gildas Cambon <gildas.cambon@ird.fr>
Date:   Mon Mar 18 14:04:31 2024 +0100

    In Preprocessing_tools, during geostrophic calculation,
    add the Ekman transport only of forcing file (containing wind strss) exists