Log elasticsearch-requests
In order to be able to analyze elasticsearch-POST-requests to our API, the content (body) of these requests should be logged in the backend. (in the backend, we add our read-only-user to incoming elasticsearch-requests and thus have a way / place where we can grab the POST-request-content)
In a next step, the requests can then be analyzed and show, for example, the usage/queries to the filter-fields or used search-terms.