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

trie/proof_test.go

@@ -106,7 +106,7 @@ func TestBadProof(t *testing.T) {
 			if proof == nil {
 				t.Fatalf("prover %d: nil proof", i)
 			}
-			it := proof.NewIterator()
+			it := proof.NewIterator(nil, nil)
 			for i, d := 0, mrand.Intn(proof.Len()); i <= d; i++ {
 				it.Next()
 			}