all: simplify and fix database iteration with prefix/start (#20808)

* core/state/snapshot: start fixing disk iterator seek

* ethdb, rawdb, leveldb, memorydb: implement iterators with prefix and start

* les, core/state/snapshot: iterator fixes

* all: remove two iterator methods

* all: rename Iteratee.NewIteratorWith -> NewIterator

* ethdb: fix review concerns

eth/filters/bench_test.go

@@ -147,7 +147,7 @@ var bloomBitsPrefix = []byte("bloomBits-")
 
 func clearBloomBits(db ethdb.Database) {
 	fmt.Println("Clearing bloombits data...")
-	it := db.NewIteratorWithPrefix(bloomBitsPrefix)
+	it := db.NewIterator(bloomBitsPrefix, nil)
 	for it.Next() {
 		db.Delete(it.Key())
 	}