VendureEntityEvent is not exported from core

[floze]

Describe the bug
I might be missing something really stupid here, but I can't find the VendureEntityEvent in the core... It doesn't seem to be exported: https://github.com/vendure-ecommerce/vendure/blob/v2.1.4/packages/core/src/event-bus/index.ts

see #2556

To Reproduce
Steps to reproduce the behavior:

1. do import { VendureEntityEvent } from '@vendure/core'
2. get '"@vendure/core"' has no exported member named 'VendureEntityEvent'. Did you mean 'VendureEntity'?

Expected behavior
VendureEntityEvent should be available from core package.

Environment (please complete the following information):

• @vendure/core version: v2.1.4