Post-clustermempool package RBF: per-chunk processing

In the discussion about transaction fees in blockchain networks, an interesting proposal suggests that child transaction fees should be capable of covering eviction costs for their parent transactions. This concept introduces a straightforward rule for wallet developers to implement: if a child transaction aims to cover the cost necessary for its parent's acceptance into the network, the fee rate of the child must exceed that of the parent. This approach ensures that both transactions are likely to be included in the same block, maintaining the integrity and efficiency of the transaction processing system. The implementation of such a rule could streamline transaction handling by simplifying the conditions under which a child transaction can support its parent, potentially improving the overall user experience when conducting transactions on the network.