EIP-7623 Increase calldata cost

[anvacaru]

Summary of changes:

• Added Ctxfloor function to calculate floor price for transactions
• Modified #finalizeTx to take an additional parameter for floor gas cost
• Updated intrinsic gas calculation with maxInt to use the higher of the standard calculation or the floor price
• Implemented helper function #tokensInCalldata to count zero and non-zero bytes
• Added required schedule constant and flag
• Updated transaction processing in driver.md to pass floor calculation to finalizeTx

Reasoning:
There are three cells used for gas computation
<gas>: gas available for current message
<callGas>: gas explicitly allocated for a particular call or sub-call in the EVM.

1. When #loadTx starts a transaction, it takes the gasLimit value of the transaction and subtracts the 21000 + (STANDARD_TOKEN_COST * tokens_in_calldata) + isContractCreation * (32000 + INITCODE_WORD_COST * words(calldata)). The result is then stored in the <gas> cell.
2. During the execution of the message, #deductGas will subtract from <gas> the cost of executing each opcode.
3. In #finalizeTx(false) rules, the refund mechanism is executed, and then the block gas used cell is incremented by GLIMIT - GAVAIL, which accounts for both the initial gas subtracted in loadTx, execution costs, and any refunds available.

To apply the new formula

tx.gasUsed = (
    21000
    +
    max(
        STANDARD_TOKEN_COST * tokens_in_calldata
        + execution_gas_used
        + isContractCreation * (32000 + INITCODE_WORD_COST * words(calldata)),
        TOTAL_COST_FLOOR_PER_TOKEN * tokens_in_calldata
    )
)

The gasUsed value with the maximum value in between GLIMIT-GAVAIL and 21000 +TOTAL_COST_FLOOR_PER_TOKEN * tokens_in_calldata.