feat(Simulations): narrow down simulation payload types

[danbillson]

Based on some recommendations after creating #51 it is a much more common pattern in this lib to use discriminated unions for this use case, originally this would have look like this:

import {
  type AddressCreatedEvent,
  type AddressImportedEvent,
  ...
} from '../../notifications/events';

export type ISimulationResponse =
  | IAddressCreatedSimulationResponse
  | IAddressUpdatedSimulationResponse
  | ...

interface BaseSimulationResponse {
  id: string;
  status: Status;
  notification_setting_id: string;
  name: string;
  last_run_at?: string | null;
  created_at: string;
  updated_at: string;
}

export interface IAddressCreatedSimulationResponse extends BaseSimulationResponse {
  type: 'address.created';
  payload?: Partial<AddressCreatedEvent['data']> | null;
}

export interface IAddressUpdatedSimulationResponse extends BaseSimulationResponse {
  type: 'address.updated';
  payload?: Partial<AddressUpdatedEvent['data']> | null;
}

...

naturally this ended up being quite exhaustive when required for ISimulationResponse, CreateSimulationRequestBody and UpdateSimulationRequestBody so this looks at an intermediary by using a helper to generate the discriminated union based on a base interface

---

The main downside to using discriminated unions over generics as looked at in #51 is that there is no way to quickly type the get simulation request other than coercing it

[samcolby]

Do we need to export this? If so, would SimulationUpdatePayloadMap be clearer?

EventPayloadMap feels quite generic

[danbillson]

Nope, doesn't need to be exported, how about SimulationEventPayloadMap?

[samcolby]

Similar naming here, should we include Simulation somewhere?

[samcolby]

Another type here we should reenable.

[samcolby]

Maybe another type here?