Fix TooExpensiveTxFilter

[marcindsobczak]

Changes:

• Stop including stale transactions when calculating cumulative cost in TooExpensiveTxFilter

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
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Testing

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[tkstanczak]

it feels like this should be a separate filter -> why the nonce check is added to the TooExpensiveTxFilter?

[marcindsobczak]

This is not a check of currently added transaction.

Due to this issue:
#3173

we started checking that the account balance is sufficient to process not only the currently added transaction, but the cumulative cost of all pending transactions of the sender's address. This introduced a bug - if we have some stale transactions for this address in TxPool, we count them when calculating cumulative cost and they block adding new transactions. This PR solves it.
I can't move it to a separate filter, because change is connected with calculating the cumulative cost, which is right here.