Create a possibility to work with aggregates having immutable identifier (e.g. data class with a val) #29
Description
Kotlin immutability is a strong feature. Based on Java implementation, aggregates members have to be mutable, to be able to get modified from the event sourcing handlers (including the aggregate identifier).
As shown on Event-Driven-Microservices 2019 conference, this can be changed (shown in Scala) by providing a special aggregate factory, which creates aggregates with at least immutable aggregate identifier.