core, trie: decode the value for storage dump (#19943)

* core, trie: decode the value for storage dump

* core/state: address comment

trie/iterator.go

@@ -34,7 +34,9 @@ type Iterator struct {
 	Err   error
 }
 
-// NewIterator creates a new key-value iterator from a node iterator
+// NewIterator creates a new key-value iterator from a node iterator.
+// Note that the value returned by the iterator is raw. If the content is encoded
+// (e.g. storage value is RLP-encoded), it's caller's duty to decode it.
 func NewIterator(it NodeIterator) *Iterator {
 	return &Iterator{
 		nodeIt: it,