feat: split reth and hera binaries (#23)

Followup from #14

Many ways to do this, but for now here's what we have:

- the `reth` binary runs the default reth CLI commands with an optional
`--hera` flag. If set, we also try to parse all `HeraArgsExt` flags and
install the ExEx on top of it. The idea is that in the future we may
have more ExExes that can be added in this way.
- `hera` binary is currently empty, but will contain the standalone
rollup node entrypoint.
- refactored `hera-exex` to its own crate, this will make it possible to
also run hera as exex from the `hera` binary as well.

Note: there is a compilation error due to
op-rs/kona#454, unrelated to this
pr.

Open to feedback

feat(kona-exex): step 1: wait for l2 genesis block

chore: typo

chore: rm useless clippy rules

chore: small type coercion

fix: commit tip before breaking loop

feat(hera): rebased on bin/ location change

chore: rename kona -> hera in cli

feat: split reth and hera binaries

chore: cargo lock

fix: last compile err

chore: add crate lints

feat: renamed bin, renamed driver, addressed pr review

chore: fmt

feat: optionally load rollup config from file

chore: rebase

chore: rebase

chore: rebase