Context:
This is a follow up ticket for this PR: https://github.com/camunda/camunda-optimize/pull/2536#discussion_r478283858

Currently, some dtos are converted with objectmappers before given to the script creation method as params (eg in ESindexAdjuster, once the above PR is merged). Let's move that logic to the writerUtil as well so you can use the script creator without having to keep in mind the mapping.

AT:

• The script creation logic with param maps in unified