[SPIKE] Mento Registry

[baroooo]

We currently use the Celo registry as an on-chain source of truth and it is used by various components of our system as a way to fetch up to date contract addresses. Since we don't own this contract we might need a new registry that we own to easily update and add new addresses in the registry.
This task aims to make an investigation and decide if we need a separate Mento governance owned registry(an alternative can be using the SDK instead) and if so how to implement and deploy that.
Also, we should investigate the external parties depending on the old registry and possibly inform them about any future changes.