Which use case/requirement will be addressed by the proposed feature?

Currently, a new instance of an ObjectMapper is created in the JsonSerde, which cannot be customized. When using Kotlin, one would like to be able to register the Kotlin Module to this ObjectMapper.

Implementation ideas

Add a secondary constructor to JsonSerde that allows you to use a custom ObjectMapper.

public JsonSerde(Class<T> objectType, ObjectMapper mapper) {
  this.mapper = mapper;
  mapper.registerModule(new JavaTimeModule());

  this.reader = mapper.readerFor(objectType);
}