Reduce number of reads from AccountState inside TxPool::SubmitTx

[deffrian]

Fixes | Closes | Resolves #

Changes:

• First filter that reads SenderAccount from state will save a copy of this data inside new struct: TxFilteringState. If any other filter needs account data it will read it from TxFilteringState. So we read account data only once.

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• [ x ] New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
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• Refactoring (no functional changes, no api changes)
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Testing

Requires testing

• [ x ] Yes
• No

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[marcindsobczak]

Overall looks good, worth to compare performance with current master

[LukaszRozmej]

I like the idea with some caveat, lets make this TxFilteringState be responsible for this account management like:

public struct TxFilteringState
{
    public Account SenderAccount { get { return _account ?? (_account = _accounts.GetAccount(_senderAddress)); } }
}

So now we can have this as lazy initialized while dropping this logic from filters.