Add binary search for creator tx hash

[kuzdogan]

Adds a new function findContractCreationTxByBinarySearch to do a lower bound binary search for the transaction that created the contract.

Calls eth_getCode on the middle blocks to see if the contract has code. If yes, the contract should be created before this block. If no code, the contract should be created after this block.
Once the block is found, searches through all the tx's of the block to see if any of them created this contract.
Only supports EOA contract creations (tx.to === null). Tracing every single tx would've been quite expensive.

Adds unit tests and an integration test for the Mainnet Tether contract to test the function.

[manuelwedler]

Tests are failing

[kuzdogan]

@manuelwedler Fixed the failing tests after we enabled binary search for finding creation transactions. The test suite was breaking because the server now uses binary search to locate transaction hashes for contract creation.

I made two main changes to resolve this:

1. Added the necessary creation data to the test cases that needed it
2. Blocked the creation transaction fetching specifically for tests that verify database updates of creation info

Please have a look at the updated tests too. The tests are now passing again.