Refactor serialization of first argument in Node class
Hi @MadhumithaKolkar It looks like your PR relates to the Keras component. Please submit it to the github.com/keras-team/keras repository instead. Thank you for your contribution! 
@fchollet, @qlzh727
Updated the `serialize_first_arg_tensor` function in the Node class to improve handling of various types of first arguments passed to layers.      
>>   - If the first argument is a Keras tensor, it is now serialized with additional metadata including the layer name, node index, and tensor index.   
>>   - For other types such as NumPy arrays, tensors, integers, floats, booleans, and strings, they are directly serialized without additional metadata.
>>   - Added a ValueError raise statement for invalid first arguments, ensuring that only supported types are accepted.
>> - Updated the `map_arguments` method documentation to reflect the changes in `serialize_first_arg_tensor`.
