[refactor] fix issue. the temporal covariate is the the anomaly of temperature smoothed with a spline

[refactor] rename folders for one/two fold fit. move the code for the anomaly into temperature_covariate.py

[refactor] move altitudes_studies.py. create trend test folder inside extreme_trend. deactivate one test for param_function that was crashing globally for unknown reason (but locally the test is working).

[exceeding] add -1 to the plot of the uncertainty curve, to show all variables display refer to the same axis. Improve uncertainty histogram plot. add the mean relative difference with the return level

[contrasting] add default pval equal to zero in gnFit (to avoid the program to crash when called by python). refactor anderson test. add anderson test by default for the one fold analysis.

[exceeding] fix code to create a qqplot. (sort only once the empirical quantiles have been computed). Create ALTITUDE_TO_GREY_MASSIF in utils to ensure that the exceedance plots are always done with the same massifs everywhere (and these massifs are only the one that are not grey for the non-stationary gev & gumbel)

[exceeding] update style of the qqplot. clean study_visualizer_for_non_stationary_trends.py, add a mode with only selected models that does not crash.

[exceeding] modify plot settings for the paper. put "imap" instead of "map" to avoid computing 2 times the models

[contrasting] add quadratic model for gumbel/gev and location/scale. modify code for the name of the models

[contrasting] add assertion that the max_abs_change is different from np.inf otherwise it makes the computer freeze
IMPORTANT MODIFICATION, THAT MIGHT CHANGE PAPER 1: change unconstrained_estimator_gev_params to unconstrained_estimator_gev_params_last_year

[exceeding] add full diagnositic plot (qqplot & intensity plots) for gumbel stationary & add gumbel gof tests from r package

[exceeding] add full diagnositic plot (qqplot & intensity plots) for gumbel stationary & add gumbel gof tests from r package