Pulling out consensus type changes from #8677.
This PR covers all type changes for spec 1.7.0-alpha.1 (except for `DataColumnSidecar` changes, which is covered in @eserilev's PR #8682)
Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>
Co-Authored-By: Michael Sproul <michael@sigmaprime.io>
Adds the required boilerplate code for the Gloas (Glamsterdam) hard fork. This allows PRs testing Gloas-candidate features to test fork transition.
This also includes de-duplication of post-Bellatrix readiness notifiers from #6797 (credit to @dapplion)