[contrasting project] add test for study loader. refactor their init function to have a better error message.

[quantile regression project]  fix bugs in daily_observations.py for the creation of the coordinates for the daily fit. some fix to prepare for some potential non stationary exponential model one day

[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.

[EUROCODE][DRAWING PER REGION] modify test region eurocode. add test_ gev temporal bayesian. add stationary version for the Bayesian. refactor utils at the root, to root_uils to avoid weird import issues.

[EXTREME ESTIMATOR] refactor margin_fits folder. extreme estimator folder. and extreme_models folder