[projection snowfall] add evgam call for abstract_temporal_linear_margin_model.py. account for log_scale in the margin_function. rename get_coord_df to get_r_dataframe_from_python_dataframe. create evgam_fixed.R for debugging

[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.