Custom Entities don't have base_field translations

Problem/Motivation

When you add a hook to be able to export the base_fields of a custom entity and it has translations the base_fields for the translation won't get exported because the hook is called for them.

Steps to reproduce

Have a custom entity with translations and create a hook for it to be able to export

Proposed resolution

Attached a patch - call the hook inside the exportBaseFields function so that when its called for the translation section the hook is also called

Remaining tasks

User interface changes

API changes

Data model changes