[SPARK-3341][SQL] The dataType of Sqrt expression should be DoubleType.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #2233 from ueshin/issues/SPARK-3341 and squashes the following commits:

e497320 [Takuya UESHIN] Fix data type of Sqrt expression.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/arithmetic.scala

@@ -36,7 +36,7 @@ case class UnaryMinus(child: Expression) extends UnaryExpression {
 case class Sqrt(child: Expression) extends UnaryExpression {
   type EvaluatedType = Any
   
-  def dataType = child.dataType
+  def dataType = DoubleType
   override def foldable = child.foldable
   def nullable = child.nullable
   override def toString = s"SQRT($child)"