Offline Batch Processing - Create required operator level functions (predict, my_input_type, transform_df, etc...)

[viswa-nvidia]

Create required operator level functions (predict, my_input_type, transform_df, etc...)

• predict -> function that calls predict against model (support any framework)
• my_input_type -> Function that returns the expected type of my inputs. (to be used by operator executor to ensure inputs are in correct format for next operator)
• transform_df -> Function that can be used to house generic operator execution behavior. Should mimic what is happening in inference op logic.