[HUDI-2330][HUDI-2335] Adding support for merge-on-read tables (#3679)

- Inserts go into logs, hashed by Kafka and Hudi partitions
 - Fixed issues with the setupKafka script
 - Bumped up the default commit interval to 300 seconds
 - Minor renaming

hudi-client/hudi-client-common/src/main/java/org/apache/hudi/client/WriteStatus.java

@@ -201,6 +201,7 @@ public class WriteStatus implements Serializable {
   public String toString() {
     final StringBuilder sb = new StringBuilder("WriteStatus {");
     sb.append("fileId=").append(fileId);
+    sb.append(", writeStat=").append(stat);
     sb.append(", globalError='").append(globalError).append('\'');
     sb.append(", hasErrors='").append(hasErrors()).append('\'');
     sb.append(", errorCount='").append(totalErrorRecords).append('\'');