Mob 1778 (Batch methods for POI categories)

@aquilax @nandy-andy @rogatty @RafLeszczynski -> This will make us do all POST requests as arrays of objects, PUT and DELETE will be available for both wildcard (with id in url) and in general entry point.
It's affecting too many vars. How about we leave it for now and make a story about refactoring all entry points?