T8n support for isStateTest and empty accounts

[shemnon]

PR description

Update t8n executor to support new isStateTest env flag that will disable extra-transactional processing such as block rewards and beacon root. Also, make sure such extra-transactional commits don't create empty accounts.

Fixed Issue(s)

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• [ ] Checked out our contribution guidelines?
• [ ] Considered documentation and added the doc-change-required label to this PR if updates are required.
• [ ] Considered the changelog and included an update if required.
• [ ] For database changes (e.g. KeyValueSegmentIdentifier) considered compatibility and performed forwards and backwards compatibility tests

Locally, you can run these tests to catch failures early:

• [ ] unit tests: ./gradlew build
• [ ] acceptance tests: ./gradlew acceptanceTest
• [ ] integration tests: ./gradlew integrationTest
• [ ] reference tests: ./gradlew ethereum:referenceTests:referenceTests

[shemnon]

Reviewer tip: hide whitespace