[HUDI-508] Standardizing on "Table" instead of "Dataset" across code (#1197)

- Docs were talking about storage types before, cWiki moved to "Table"
 - Most of code already has HoodieTable, HoodieTableMetaClient - correct naming
 - Replacing renaming use of dataset across code/comments
 - Few usages in comments and use of Spark SQL DataSet remain unscathed

hudi-spark/src/test/java/HoodieJavaApp.java

@@ -45,7 +45,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * Sample program that writes & reads hoodie datasets via the Spark datasource.
+ * Sample program that writes & reads hoodie tables via the Spark datasource.
  */
 public class HoodieJavaApp {
 

hudi-spark/src/test/java/HoodieJavaStreamingApp.java

@@ -45,7 +45,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 
 /**
- * Sample program that writes & reads hoodie datasets via the Spark datasource streaming.
+ * Sample program that writes & reads hoodie tables via the Spark datasource streaming.
  */
 public class HoodieJavaStreamingApp {