Merge arrays should replace by default

For serverless workflow, array merging should basically replace the src property array with the target property array.
So we are going to change the interpretaion of the boolean parameter of MergeUtils.merge
Before this JIRA, the code always try to merge the two arrays (an union), and the boolean just indicates if duplicates should be skipped
Now the boolean indicated whether the array should be merged (true) or replaced (false). Therefore true is equivalent to previous behaviour when skipDuplicate was true (this is the expected behaviour for JsonSchema generation), And by default (false), the array will be replaces, which is the desired behaviour for Serverless Workflow action