[AutoML API] API Suggestions

- When setting evaluation metrics using methods like `SetBinaryClassificationMetric`, the default value for `labelColumn` parameter is *label*. This is inconsistent with like the `predictColumn` parameter and the rest of ML.NET. Suggest change to `Label`.
- When setting evaluation metrics using methods like `SetBinaryClassificationMetric`, the parameter names are `labelColumn` and `predictColumn`. In ML.NET, typically parameters referring to column names include name. Suggest change of parameter names to `labelColumnName` and `predictColumnName`.