Traction control

The pre-release v1.0.0-beta.4 is a mammoth of an execution-apis release.

There are far to many changes over the last year to dive deeply into any of them, but a few highlights:

• Proto-spec for Prague is available for devnet-0 work.
• The test generation tooling has changed a bit, thanks to the work of @fjl. The testing chain is now created using hivechain.
• The eth namespace endpoints were updated for Cancun.
• mining namespace was completely removed.

Full Changelog: v1.0.0-beta.3...v1.0.0-beta.4