* 1.Remove import doris via csv in Dataxwriter, only support via json; 2.Format Dataxwriter code; 3.Optimize exception handling and reduce multiple output of exception logs; 4.Update the dataxwriter's documentation; * Delete DorisCsvCodec.java delete unused file extension/DataX/doriswriter/src/main/java/com/alibaba/datax/plugin/writer/doriswriter/DorisCsvCodec.java * 1.remove `format` config key; 2.Optimize serialization code in DorisJsonCodec class