Fix and restore disabled block creation unit tests

[fab-10]

PR description

Disabled block creation unit tests have been updated and fixed and re-enabled, this required to rework the ExecutionContextTestFixture to accept the genesis file to use, instead of using an hard-coded one as before, and for this there are more file changed/added

Fixed Issue(s)

fixes #6850

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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