Performance and error handling enhancements

[dipinhora]

Sadly, too much stuff got intermingled so this is one huge commit instead of logically separated commits of things. 8*/

Includes:

• Initial version of performance testing app
• Performance related changes to avoid unnecessary allocations and to keep the payload of a kafka message as iso for consumers
• addition of an IsoReader for efficient read no copy read buffer
• Additioan of Reader and PeekableReader traits
• updated to codecs to be able to use either IsoReader or ValReader
• revert logger to use outstream instead of printf again
• fix reconnection logic issue (use of this instead of conn)
• deprecate KafkaMessage class and replace with iso array for value, val array or None for key, and KafkaMessageMetadata for metadata
• error handling improvements everywhere
• simple cli arguments parser for most config options
• ability to specify offset for where to start reading messages from kafka
• misc scripts for starting a kafka cluster for manual testing