Translation of the Elixir EntryGenesis module.
This module exposes static genesis values (signer, PoP, attestation, entry)
and provides a deterministic builder + signer for the genesis entry.
Some Elixir dependencies (BIC.Base.call_exit) are not implemented in Rust yet; see generate().
Generate the same tuple as the Elixir generate/0 would: {entry_signed, attestation, pop}.
NOTE: at the moment, some required building blocks are not implemented in Rust: