[quantile regression project] refactor imports for quantile estimators. two fix: nb_obs=1 in GevSimulation.py and df_merged correspond to df_coordinates from now on (such as it takes into account the transformation if there is one)

[refactor] refactor test_quantile_estimator.py. Quantile estimators works for any temporal coordinates.

[refactor] remove scores. remove non_stationary_trends, delete univariate_test_results that was deprecated

[paper 1] add plot for the presentation. increase the size of the legend for uncertainty curves. add sample function for the GevParams class.

[paper 1] modify the source of data (use the last version from AERIS) and shift the year being used (now study go from 1959 to 2019)

[paper 2] rename safran precipitation total to safran precipitation. add snowfall, precipitation, and rainfall study classes for 1, 3, 5 and 7 days