Add more unit tests

Little naming cleanup (first round)

src/basic_data_handling/casting_nodes.py

@@ -51,7 +51,7 @@ class CastToInt:
     def convert_to_int(self, input: Any) -> tuple[int]:
         try:
             return (int(input),)
-        except ValueError:
+        except (ValueError, TypeError):
             raise ValueError(f"Cannot convert {input} to an INT.")
 
 
@@ -79,7 +79,7 @@ class CastToFloat:
     def convert_to_float(self, input: Any) -> tuple[float]:
         try:
             return (float(input),)
-        except ValueError:
+        except (ValueError, TypeError):
             raise ValueError(f"Cannot convert {input} to a FLOAT.")