[R Model] refactor directory names.

test/test_extreme_estimator/test_max_stable_estimators.py

 import unittest
 
-from extreme_estimator.R_fit.max_stable_fit.abstract_max_stable_model import \
+from extreme_estimator.R_model.max_stable_model.abstract_max_stable_model import \
     AbstractMaxStableModelWithCovarianceFunction, CovarianceFunction
-from extreme_estimator.R_fit.max_stable_fit.max_stable_models import Smith, BrownResnick, Schlather, \
+from extreme_estimator.R_model.max_stable_model.max_stable_models import Smith, BrownResnick, Schlather, \
     Geometric, ExtremalT, ISchlather
 from extreme_estimator.estimator.max_stable_estimator import MaxStableEstimator
 from spatio_temporal_dataset.dataset.simulation_dataset import MaxStableDataset

utils.py

-import os
 import os.path as op
 
 
 def get_root_path() -> str:
-    return os.path.dirname(os.path.abspath(__file__))
+    return op.dirname(op.abspath(__file__))
 
 
 def get_full_path(relative_path: str) -> str: