` events_mgmt` : need a way to add multiple EventsOfInterest when registering a new event consumer

### There should be a way to add multiple ProviderId/EventCode combinations when registering an event consumer using this library.

### Currently, there is no way to add multiple EventsOfInterest while registering an event consumer using this library. We need a way to

### Reproduce Scenario (including but not limited to)
Optional created = this.registrationService.createRegistration(
RegistrationInputModel.builder()
.description(this.eventConsumerConfig.event_registration_description())
.name(this.eventConsumerConfig.event_registration_name())

//Only allows one combination of provider and event code!
//What If i want to add more than one combination to listen to in this journal?
.addEventsOfInterests(EventsOfInterest.builder()
.setEventCode(this.eventConsumerConfig.aio_event_code())
.setProviderId(providerId).build())
);
#### Steps to Reproduce
See above

#### Platform and Version
Java 11

#### Sample Code that illustrates the problem
See above

#### Logs taken while reproducing problem
N/A because i cannot add multiple EventsOfInterest

Start with RegistrationInputModel.builder(), addEventsOfInterests(), and registrationService.createRegistration() in the example. Trace how EventsOfInterest is stored during registration, then make the registration accept multiple ProviderId/EventCode combinations. Done means a consumer can register with more than one EventsOfInterest; verify this with a Java 11 example or test if one exists.

Written by the indexing model from the issue text.