feat: Implement set_custom_formatters as a one unified gateway function

[jopemachine]

Ref: https://github.com/lablup/backend.ai/pull/2105/files#r1595126303

Now, we need to improve code readability, not just write code that works, for integration and maintenance.
Let's handle the callback functions that specify formatters in Python through a single gateway function, instead of calling each one individually.

Before

def register_custom_deserializer() -> None:
    """
    Initialize the custom deserializers.
    """

    set_confchange_context_deserializer(pickle_deserialize)
    set_confchangev2_context_deserializer(pickle_deserialize)
    set_entry_context_deserializer(pickle_deserialize)
    set_entry_data_deserializer(pickle_deserialize)
    set_message_context_deserializer(pickle_deserialize)
    set_snapshot_data_deserializer(pickle_deserialize)

After

def register_custom_deserializer() -> None:
    """
    Initialize the custom deserializers.
    """

    set_custom_formatters(
        entry_data=pickle_deserialize,
        entry_context=pickle_deserialize,
        confchange_context=pickle_deserialize,
        confchangev2_context=pickle_deserialize,
        message_context=pickle_deserialize,
        snapshot_data=pickle_deserialize,
        log_entry=pickle_deserialize,
        fsm=pickle_deserialize,
    )