NewEventStore creates a new EventStore with a Postgres URI: `postgres://user:password@hostname:port/db?options`.

WithEventHandler adds an event handler that will be called after saving events.

WithEventHandlerInTX adds an event handler that will be called during saving of events.

EventStore is an eventhorizon.EventStore for PostgreSQL, using one collection for all events and another to keep track of all aggregates/streams.

Option is an option setter used to configure creation.