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

common/bytes.go

@@ -145,3 +145,14 @@ func TrimLeftZeroes(s []byte) []byte {
 	}
 	return s[idx:]
 }
+
+// TrimRightZeroes returns a subslice of s without trailing zeroes
+func TrimRightZeroes(s []byte) []byte {
+	idx := len(s)
+	for ; idx > 0; idx-- {
+		if s[idx-1] != 0 {
+			break
+		}
+	}
+	return s[:idx]
+}