Implement new RBF logic for cluster mempool

With a total ordering on mempool transactions, we are now able to calculate a
transaction's mining score at all times. Use this to improve the RBF logic:

- we no longer enforce a "no new unconfirmed parents" rule

- we now require that the mempool's feerate diagram must improve in order
  to accept a replacement

- the topology restrictions for conflicts in the package rbf setting have been
  eliminated

Revert the temporary change to mempool_ephemeral_dust.py that were previously
made due to RBF validation checks being reordered.

Co-authored-by: Gregory Sanders <gsanders87@gmail.com>, glozow <gloriajzhao@gmail.com>

test/functional/mempool_truc.py

@@ -513,7 +513,7 @@ class MempoolTRUC(BitcoinTestFramework):
         tx_v3_child_2_rule6 = self.wallet.create_self_transfer(
             utxo_to_spend=tx_v3_parent["new_utxos"][1], fee_rate=DEFAULT_FEE, version=3
         )
-        rule6_str = f"insufficient fee (including sibling eviction), rejecting replacement {tx_v3_child_2_rule6['txid']}; new feerate"
+        rule6_str = f"insufficient fee (including sibling eviction), rejecting replacement {tx_v3_child_2_rule6['txid']}"
         assert_raises_rpc_error(-26, rule6_str, node.sendrawtransaction, tx_v3_child_2_rule6["hex"])
         self.check_mempool([tx_v3_parent['txid'], tx_v3_child_1['txid']])
 
@@ -544,11 +544,6 @@ class MempoolTRUC(BitcoinTestFramework):
         tx_v3_replacement_only = self.wallet.create_self_transfer_multi(utxos_to_spend=utxos_for_conflict, fee_per_output=4000000)
         # Override maxfeerate - it costs a lot to replace these 100 transactions.
         assert node.testmempoolaccept([tx_v3_replacement_only["hex"]], maxfeerate=0)[0]["allowed"]
-        # Adding another one exceeds the limit.
-        utxos_for_conflict.append(tx_v3_parent["new_utxos"][1])
-        tx_v3_child_2_rule5 = self.wallet.create_self_transfer_multi(utxos_to_spend=utxos_for_conflict, fee_per_output=4000000, version=3)
-        rule5_str = f"too many potential replacements (including sibling eviction), rejecting replacement {tx_v3_child_2_rule5['txid']}; too many potential replacements (101 > 100)"
-        assert_raises_rpc_error(-26, rule5_str, node.sendrawtransaction, tx_v3_child_2_rule5["hex"])
         self.check_mempool(txids_v2_100 + [tx_v3_parent["txid"], tx_v3_child_1["txid"]])
 
         self.log.info("Test sibling eviction is successful if it meets all RBF rules")
@@ -566,7 +561,7 @@ class MempoolTRUC(BitcoinTestFramework):
         fee_to_beat = max(int(tx_v3_child_2["fee"] * COIN), int(tx_unrelated_replacee["fee"]*COIN))
 
         tx_v3_child_3 = self.wallet.create_self_transfer_multi(
-            utxos_to_spend=[tx_v3_parent["new_utxos"][0], utxo_unrelated_conflict], fee_per_output=fee_to_beat*2, version=3
+            utxos_to_spend=[tx_v3_parent["new_utxos"][0], utxo_unrelated_conflict], fee_per_output=fee_to_beat*4, version=3
         )
         node.sendrawtransaction(tx_v3_child_3["hex"])
         self.check_mempool(txids_v2_100 + [tx_v3_parent["txid"], tx_v3_child_3["txid"]])