generateNewPreKeys
open suspend override fun generateNewPreKeys(firstKeyId: Int, keysCount: Int): Either<ProteusFailure, List<<Error class: unknown class>>>
Generate prekeys to be uploaded to the backend and shared with other clients in order to initialise a new conversation with this client.
As these are consumed, we should keep uploading new prekeys to the backend. For this reason, these can be called "rolling" prekeys, in an attempt to separate them from the "last resort" prekey, which is described in generateNewLastResortKey.