[HUDI-2394] Implement Kafka Sink Protocol for Hudi for Ingesting Immutable Data (#3592)

- Fixing packaging, naming of classes
 - Use of log4j over slf4j for uniformity
- More follow-on fixes
 - Added a version to control/coordinator events.
 - Eliminated the config added to write config
 - Fixed fetching of checkpoints based on table type
 - Clean up of naming, code placement

Co-authored-by: Rajesh Mahindra <rmahindra@Rajeshs-MacBook-Pro.local>
Co-authored-by: Vinoth Chandar <vinoth@apache.org>

hudi-utilities/src/main/java/org/apache/hudi/utilities/deltastreamer/DeltaSync.java

@@ -352,6 +352,7 @@ public class DeltaSync implements Serializable {
         }
       }
     } else {
+      // initialize the table for the first time.
       String partitionColumns = HoodieSparkUtils.getPartitionColumns(keyGenerator, props);
       HoodieTableMetaClient.withPropertyBuilder()
           .setTableType(cfg.tableType)

hudi-utilities/src/main/java/org/apache/hudi/utilities/schema/SchemaProvider.java

@@ -29,7 +29,8 @@ import org.apache.spark.api.java.JavaSparkContext;
 import java.io.Serializable;
 
 /**
- * Class to provide schema for reading data and also writing into a Hoodie table.
+ * Class to provide schema for reading data and also writing into a Hoodie table,
+ * used by deltastreamer (runs over Spark).
  */
 @PublicAPIClass(maturity = ApiMaturityLevel.STABLE)
 public abstract class SchemaProvider implements Serializable {