Create ed25519 proto compatible with ADR-28

[robert-zaremba]

Summary

Some chains will like to opt-in for ed25519 for user accounts. Let's implement an ADR-28 compatible keys for them.

Ref: #8543 (comment)

Problem Definition

Currently, we don't support ed25519 for user keys. Custom implementation could not be compatible with ADR-28 and could lead to potential design conflicts in the future.

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[alexanderbez]

Title is off

[IdaTucker]

@robert-zaremba is this something which is still of interest?

[ainhoa-a]

We're working on this #7315 and believe when merging it will cover the proto message requested here.

[bizk]

Started working into this issue

[bizk]

Got the implementation of said ADR address, seems it provoked errors on nodes and validators. This won't be backwards compatible so I'm working on figuring out how severe is the impact, are we sure we want to proceed with this? @tac0turtle

cc: @raynaudoe @JulianToledano

[bizk]

It affects the validators and the block interaction, seems like when a validator is initialized with an ed25519 key with the new address it is unable to receive blocks, or a block is unable to find such validator. It is still unclear what is causing the misscomunication on the existing tests if nor the keys neither the addresses are being hardcoded