Improve conformance tests

[Soupstraw]

• [ ] Add support for inline datums
• [ ] Add support for Plutus scripts
• [ ] Generate cases with multiple copies of the same type of certificate (currently they're all unique)
• [ ] Add support for withdrawals
• [ ] Add support for pool re-registration
• [ ] Add support for RegKey and UnRegKey
• [ ] Proposals and governance actions
• [ ] Add more rules
• [ ] Run trace tests