Create and use global allowlist for pruning mempools

[murchandamus]

We only use transactions that were eventually included in the blockchain as it is otherwise hard to impossible to get all relevant meta data. Currently, mempools are pruned per the allowlist created from the transactions that occurred in the same month. If we instead used an allowlist created from all months this would give our blockbuilders a bigger set of transactions to work with, especially towards the end of a month when the mempool is not empty.

A simple approach would be to also include the transactions from blocks until the next time the mempool fully cleared after the end of the month. A more comprehensive approach would be to train a cuckoo filter on all transactions confirmed starting with the first month we consider and use that as a replacement of an allowlist explicitly encompassing all transactions.