Meta data of files being ingested to be provided in Data mapper

[#1]

Description -

Why is this feature important to you - this helps in debugging in case of any failures.

How would you like the feature to work - File name should be made available in list of fields available so that it can be mapped to a field in schema.

Current Behaviour - No such information is available so that we can link a batch to a file name and use that for debugging.