[fix][common] Fix issue that decimal value is cut when scale is 0.

Author: nokiaMS

common/src/main/java/io/dingodb/expr/common/type/DecimalType.java

@@ -33,7 +33,7 @@ public final class DecimalType extends ScalarType {
     @Setter
     private long scale;
 
-    DecimalType() {
+    public DecimalType() {
         super();
     }