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

core/state/snapshot/iterator.go

@@ -148,10 +148,10 @@ type diskAccountIterator struct {
 
 // AccountIterator creates an account iterator over a disk layer.
 func (dl *diskLayer) AccountIterator(seek common.Hash) AccountIterator {
-	// TODO: Fix seek position, or remove seek parameter
+	pos := common.TrimRightZeroes(seek[:])
 	return &diskAccountIterator{
 		layer: dl,
-		it:    dl.diskdb.NewIteratorWithPrefix(rawdb.SnapshotAccountPrefix),
+		it:    dl.diskdb.NewIterator(rawdb.SnapshotAccountPrefix, pos),
 	}
 }