feat: purge mempool based on chain events

[agaffney]

We re-run validation on all TXs in the mempool when the chain is updated. This serves to purge TXs based on spent UTxOs and TTL

[agaffney]

{"time":"2025-03-13T14:41:24.899587881-04:00","level":"DEBUG","msg":"submit tx","component":"connmanager","component":"network","protocol":"local-tx-submission","role":"server","connection_id":"dingo.socket<->unix@602"}
{"time":"2025-03-13T14:41:24.901767224-04:00","level":"DEBUG","msg":"added transaction","component":"mempool","tx_hash":"9fc6fb4ee23861b3097006b34bd65aade46ea6f198f19fc4f7d65c7578ce295e"}
...
{"time":"2025-03-13T14:41:51.117006302-04:00","level":"INFO","msg":"chain extended, new tip: 4391101fd372b67f73b96c224ca7bef842fe29af87f115825afceeaf141d8d0d at slot 75235311","component":"ledger"}
...
{"time":"2025-03-13T14:43:42.34921325-04:00","level":"DEBUG","msg":"removed transaction after re-validation failure","component":"mempool","tx_hash":"9fc6fb4ee23861b3097006b34bd65aade46ea6f198f19fc4f7d65c7578ce295e","error":"TX 9fc6fb4ee23861b3097006b34bd65aade46ea6f198f19fc4f7d65c7578ce295e failed validation: bad input(s): dbdbd434a1e8a08a3ed25e8aad40b342f8a278c4ee5906b30922a79a2eef4b85#0\nvalue not conserved: consumed 0, produced 609547154"}