Migrate data source errors to domain

[iamacook]

We currently have a layer of abstration for data source errors. We should remove this and instead map errors to domain-specific ones, e.g. "non-existent Safe address" to improve errors and reduce complexity.

On the client side, we can have global, domain-specific error filters (reviewing those ones that we currently have).

The email domain is a good point of the reference. The data source (database) knows about the domain, throwing domain-specific errors.