fix : datetime is not json serializable

[SidduHussain]

On selecting jsonl as target type

• All datetime type schema properties were failing with the error (datetime is not JSON serializable).
• You can simply enable the config include_process_date, and this error will appear with format_type: jsonl.
• Added custom JSON serializer which is already used to fix issue bug: TypeError: Object of type datetime is not JSON serializable #1