ModuleDSL definition

[johanhaleby]

It would be good to differentiate between an initialized module and a ModuleDefintion. E.g. this would be nice:

val moduleDefinition = module(name = "something") {
    commands {
      ...
    }
    sagas {
      ...
    }
    policies/triggers {
      ...
    }
}

moduleDefinition.initialize(eventStore, subscriptionModel, domainQueries, ...)

ModuleDefinition is just data which means that it's easier to compose. Note that it must be possible to compose modules and not only module definitons, since for certain modules you may want different event store implementations or subscription models etc.