Make pronunciation dictionary a translatable entity

Problem/Motivation

Dictionary is more of a basic configuration. Make it a translatable entity instead. Allows it also to eventually scale further if needed.

Steps to reproduce

Currently very basic, won't be able to scale if it needs to. E.g. to handle things like #3587061: Allow per content item pronunciation control dictionary items

Proposed resolution

Consider how to build this + build it

Remaining tasks

TBD

User interface changes

TBD

API changes

TBD

Data model changes

TBD