Extend framework to support eip-7928 BAL

[raxhvl]

It would be nice to have an update to https://github.com/ethereum/execution-spec-tests/blob/main/src/ethereum_test_fixtures/blockchain.py where we plan to include the BAL in the pydantic model to both the blockchain and blockchain-engine tests, to have a better idea on how this ends up in the fixture.

Originally posted by @marioevz in #1823 (comment)

[jwasinger]

We should also modify and refill all tests which use balances larger than 16 bytes. BALs introduce a max balance of 2**(16*8)-1. A lot of tests use larger balances.