New genesis processing

[MissingNO57]

Using changes from #243

Replaced original genesis processing with the new one.

TODO:

• Add contracts manager tests

Code Review Checklist (to be filled out by reviewer)

• [x] Description accurately reflects what changes are being made.
• [x] Either the PR references an issue (via the "Development" combobox) or the description explains the need for the changes.
• [x] The PR appropriately sized.
• [x] The PR contains an idempotent DB migration.
• [x] I have verified the correctness of the DB migration using relevant data (e.g. test-generated data).
• [x] New code has enough tests.
• [x] New code has enough documentation to answer "how do I use it?" and "what does it do?".
• [x] Existing documentation is up-to-date, if impacted.