cmd, core, eth: background transaction indexing (#20302)

* cmd, core, eth: init tx lookup in background

* core/rawdb: tiny log fixes to make it clearer what's happening

* core, eth: fix rebase errors

* core/rawdb: make reindexing less generic, but more optimal

* rlp: implement rlp list iterator

* core/rawdb: new implementation of tx indexing/unindex using generic tx iterator and hashing rlp-data

* core/rawdb, cmd/utils: fix review concerns

* cmd/utils: fix merge issue

* core/rawdb: add some log formatting polishes

Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: Péter Szilágyi <peterke@gmail.com>

eth/handler.go

@@ -72,6 +72,7 @@ type ProtocolManager struct {
 
 	txpool     txPool
 	blockchain *core.BlockChain
+	chaindb    ethdb.Database
 	maxPeers   int
 
 	downloader   *downloader.Downloader
@@ -108,6 +109,7 @@ func NewProtocolManager(config *params.ChainConfig, checkpoint *params.TrustedCh
 		eventMux:   mux,
 		txpool:     txpool,
 		blockchain: blockchain,
+		chaindb:    chaindb,
 		peers:      newPeerSet(),
 		whitelist:  whitelist,
 		txsyncCh:   make(chan *txsync),