Allow all Appenders to optionally carry a Property array

Allow all Appenders to optionally carry a Property array. This allows 3rd party tooling to read and write properties for their own use.

This refactoring pulls up the properties instance variable and methods from org.apache.logging.log4j.kafka.appender.KafkaAppender.Builder to org.apache.logging.log4j.core.filter.AbstractFilterable.Builder.

This task is only applicable to Appender that implement the Builder pattern.