[EXTREME ESTIMATOR][MAX STABLE] add test that check the possibility to fit max stable with 3D coordinates. This is working with all the max stable structure except Smith structure (see max_stable_fit.R for an example of the returned error)

[COORDINATE] refactor starting year & df_temporal_coordinates. to normalize the same way any temporal covariate. So that each fit has the same type of normalized data as input. add multiple transformation.

[SCM][HYPERCUBE] normalize gev trend_strength with distance between years. update test to check this distance.

[COORDINATES] add some normalization class for the coordinate, add a normalization function for the observations.

[COORDINATES] add one test to test_transformation. add some copying during coordinate transformation.

[DATASET] add creation of spatio temporal dataset from simulation. add test for non stationarity of max stable

[TEST][DATASET] major fix for abstract_dataset for the function transform_maxima in the spatio temporal case

[SIMULATION] add constant estimators. handle graph plot of constant margin estimator (when the sampling margin was also constant)