Check for why the "vertx-postgres" and the "vertx-web-kotlin-dsljson-…

…postgresql" portions perform about 25% better in the data updates test

It seems a more complicated update SQL is used to replace a batch update call. See TechEmpower@9dffd6a and the cached prepared query array in the code for more details. This technique is rather niche so I temporarily do not adopt it in the "vertx-web-kotilnx" portion.