Support defining static column name as arg

aleksis/apps/csv_import/field_types.py

@@ -72,6 +72,8 @@ class FieldType:
 
     def get_column_name(self) -> str:
         """Get column name for use in Pandas structures."""
+        if self.get_args().get("column_name"):
+            return self.get_args()["column_name"]
         return self.column_name
 
     def __init__(self, school_term: SchoolTerm, base_path: str):