routing: add block cache to BitcoindFilteredChainView

This commit adds the block cache to the BitcoindFilteredChainView struct
and wraps its GetBlock function so that block cache is used.

routing/chainview/interface_test.go

@@ -26,6 +26,7 @@ import (
 	_ "github.com/btcsuite/btcwallet/walletdb/bdb" // Required to register the boltdb walletdb implementation.
 
 	"github.com/lightninglabs/neutrino"
+	"github.com/lightningnetwork/lnd/blockcache"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/kvdb"
 )
@@ -844,7 +845,11 @@ var interfaceImpls = []struct {
 				cleanUp2()
 			}
 
-			chainView := NewBitcoindFilteredChainView(chainConn)
+			blockCache := blockcache.NewBlockCache(10000)
+
+			chainView := NewBitcoindFilteredChainView(
+				chainConn, blockCache,
+			)
 
 			return cleanUp3, chainView, nil
 		},