* scaffolding for verification package
* WIP blob verification methods
* lock wrapper for safer forkchoice sharing
* more solid cache and verification designs; adding tests
* more test coverage, adding missing cache files
* clearer func name
* remove forkchoice borrower (it's in another PR)
* revert temporary interface experiment
* lint
* nishant feedback
* add comments with spec text to all verifications
* some comments on public methods
* invert confusing verification name
* deep source
* remove cache from ProposerCache + gaz
* more consistently early return on error paths
* messed up the test with the wrong config value
* terence naming feedback
* tests on BeginsAt
* lint
* deep source...
* name errors after failure, not expectation
* deep sooource
* check len()==0 instead of nil so empty lists work
* update test for EIP-7044
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Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>