fix: faults not added to features because using string not enum

Author: Lachlan Grose

LoopStructural/modelling/core/geological_model.py

@@ -1184,7 +1184,7 @@ def _add_faults(self, feature_builder, features=None):
         for f in reversed(features):
             if isinstance(f, str):
                 f = self.__getitem__(f)
-            if f.type == "fault":
+            if f.type == FeatureType.FAULT:
                 feature_builder.add_fault(f)
             # if f.type == 'unconformity':
             #     break