New version of the CSVSource

[daniil-quix]

A new version of CSVSource to make it more flexible:

• No need to pack the message value to a field. Every column is produced to Kafka now
• Added optional "key_extractor" and "timestamp_extractor" callables to specify Kafka keys and timestamps based on the row
• Added optional delay param to sleep between the rows for simulation

Breaking change:

• The "name" parameter is required now (previously the filename was used as a name)
• key_serializer and value_serializer params have been removed.