EIP-2929 Gas Cost Increases

Documentation for tests/berlin/eip2929_gas_cost_increases@244852ff.

Generate fixtures for these test cases for Prague with:

fill -v tests/berlin/eip2929_gas_cost_increases --fork Prague

Tests EIP-2929: Gas cost increases for state access opcodes

Test cases for EIP-2929: Gas cost increases for state access opcodes.