[SPARK-14642][SQL] import org.apache.spark.sql.expressions._ breaks udf under functions

## What changes were proposed in this pull request?

PR fixes the import issue which breaks udf functions.

The following code snippet throws an error

```
scala> import org.apache.spark.sql.functions._
import org.apache.spark.sql.functions._

scala> import org.apache.spark.sql.expressions._
import org.apache.spark.sql.expressions._

scala> udf((v: String) => v.stripSuffix("-abc"))
<console>:30: error: No TypeTag available for String
       udf((v: String) => v.stripSuffix("-abc"))
```

This PR resolves the issue.

## How was this patch tested?

patch tested with unit tests.

(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Author: Subhobrata Dey <sbcd90@gmail.com>

Closes #12458 from sbcd90/udfFuncBreak.

external/java8-tests/src/test/java/org/apache/spark/sql/Java8DatasetAggregatorSuite.java

@@ -25,7 +25,7 @@ import scala.Tuple2;
 
 import org.apache.spark.sql.Dataset;
 import org.apache.spark.sql.KeyValueGroupedDataset;
-import org.apache.spark.sql.expressions.java.typed;
+import org.apache.spark.sql.expressions.javalang.typed;
 
 /**
  * Suite that replicates tests in JavaDatasetAggregatorSuite using lambda syntax.

sql/core/src/main/java/org/apache/spark/sql/expressions/java/typed.java → sql/core/src/main/java/org/apache/spark/sql/expressions/javalang/typed.java

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark.sql.expressions.java;
+package org.apache.spark.sql.expressions.javalang;
 
 import org.apache.spark.annotation.Experimental;
 import org.apache.spark.api.java.function.MapFunction;
@@ -29,7 +29,7 @@ import org.apache.spark.sql.execution.aggregate.TypedSumLong;
  * :: Experimental ::
  * Type-safe functions available for {@link org.apache.spark.sql.Dataset} operations in Java.
  *
- * Scala users should use {@link org.apache.spark.sql.expressions.scala.typed}.
+ * Scala users should use {@link org.apache.spark.sql.expressions.scalalang.typed}.
  *
  * @since 2.0.0
  */

sql/core/src/main/scala/org/apache/spark/sql/expressions/scala/typed.scala → sql/core/src/main/scala/org/apache/spark/sql/expressions/scalalang/typed.scala

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.spark.sql.expressions.scala
+package org.apache.spark.sql.expressions.scalalang
 
 import org.apache.spark.annotation.Experimental
 import org.apache.spark.sql._
@@ -25,7 +25,7 @@ import org.apache.spark.sql.execution.aggregate._
  * :: Experimental ::
  * Type-safe functions available for [[Dataset]] operations in Scala.
  *
- * Java users should use [[org.apache.spark.sql.expressions.java.typed]].
+ * Java users should use [[org.apache.spark.sql.expressions.javalang.typed]].
  *
  * @since 2.0.0
  */

sql/core/src/test/java/test/org/apache/spark/sql/sources/JavaDatasetAggregatorSuite.java

@@ -30,7 +30,7 @@ import org.apache.spark.sql.Encoder;
 import org.apache.spark.sql.Encoders;
 import org.apache.spark.sql.KeyValueGroupedDataset;
 import org.apache.spark.sql.expressions.Aggregator;
-import org.apache.spark.sql.expressions.java.typed;
+import org.apache.spark.sql.expressions.javalang.typed;
 
 /**
  * Suite for testing the aggregate functionality of Datasets in Java.

sql/core/src/test/scala/org/apache/spark/sql/DatasetAggregatorSuite.scala

@@ -21,7 +21,7 @@ import scala.language.postfixOps
 
 import org.apache.spark.sql.catalyst.encoders.ExpressionEncoder
 import org.apache.spark.sql.expressions.Aggregator
-import org.apache.spark.sql.expressions.scala.typed
+import org.apache.spark.sql.expressions.scalalang.typed
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.test.SharedSQLContext
 

sql/core/src/test/scala/org/apache/spark/sql/DatasetBenchmark.scala

@@ -19,7 +19,7 @@ package org.apache.spark.sql
 
 import org.apache.spark.{SparkConf, SparkContext}
 import org.apache.spark.sql.expressions.Aggregator
-import org.apache.spark.sql.expressions.scala.typed
+import org.apache.spark.sql.expressions.scalalang.typed
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.types.StringType
 import org.apache.spark.util.Benchmark

sql/core/src/test/scala/org/apache/spark/sql/execution/WholeStageCodegenSuite.scala

@@ -20,7 +20,7 @@ package org.apache.spark.sql.execution
 import org.apache.spark.sql.Row
 import org.apache.spark.sql.execution.aggregate.TungstenAggregate
 import org.apache.spark.sql.execution.joins.BroadcastHashJoinExec
-import org.apache.spark.sql.expressions.scala.typed
+import org.apache.spark.sql.expressions.scalalang.typed
 import org.apache.spark.sql.functions.{avg, broadcast, col, max}
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.sql.types.{IntegerType, StringType, StructType}

sql/core/src/test/scala/org/apache/spark/sql/streaming/StreamingAggregationSuite.scala

@@ -24,7 +24,7 @@ import org.apache.spark.sql.StreamTest
 import org.apache.spark.sql.catalyst.analysis.Update
 import org.apache.spark.sql.execution.streaming._
 import org.apache.spark.sql.execution.streaming.state.StateStore
-import org.apache.spark.sql.expressions.scala.typed
+import org.apache.spark.sql.expressions.scalalang.typed
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.test.SharedSQLContext