`TOPIC_PREFIX` is now mandatory to all connectors therefore it make
sense to have it in common config. Beside that, it also makes it more
easy to use it in Debezium UI without any workarounds - if the field is
not member of the given connector config, the field has to be
explicitely added into known fields otherwise is invisible for UI.
* Consolidated converts to simply OracleValueConverters
* Defined a common interface for legacy and new DML parsers
* Parser failures now through exception rather than skip event
* Added support for "Unsupported Type" in DML parsing (spatial columns)
* Units encoded into JMX metrics names
* Additional JMX metrics added & some metrics calculations improved
* Introduced JMH benchmarks for Oracle LogMiner parser & end-to-end
