Datagen add binary & varbinary type support

Datagen connector currently not support BYTES type. e.g. BINARY & VARBINARY. It will cause exception when use

CREATE TABLE t3 (
f0 BIGINT,
f1 VARBINARY
) WITH (
'connector' = 'datagen',
....
);

StackTrace:
Caused by: org.apache.flink.table.api.ValidationException: Unsupported type: BYTES at org.apache.flink.connector.datagen.table.RandomGeneratorVisitor.defaultMethod(RandomGeneratorVisitor.java:317) at org.apache.flink.connector.datagen.table.RandomGeneratorVisitor.defaultMethod(RandomGeneratorVisitor.java:60) at org.apache.flink.table.types.logical.utils.LogicalTypeDefaultVisitor.visit(LogicalTypeDefaultVisitor.java:82) at org.apache.flink.table.types.logical.VarBinaryType.accept(VarBinaryType.java:151) at org.apache.flink.connector.datagen.table.DataGenTableSourceFactory.createContainer(DataGenTableSourceFactory.java:128) at org.apache.flink.connector.datagen.table.DataGenTableSourceFactory.createDynamicTableSource(DataGenTableSourceFactory.java:98) at org.apache.flink.table.factories.FactoryUtil.createTableSource(FactoryUtil.java:147)