Require lexicographic ordering for metadata feat

tips/TIP-0038/tip-0038.md

@@ -858,6 +858,7 @@ Feature</i>: smart contract request parameters are encoded in the metadata field
 - Each `Key` in the `Entries` must consist only of bytes that are printable ASCII characters, that is, for each
   character `char` (interpreted as a byte) in the `Key` it must hold: `33 <= char <= 126`.
 - Each `Key` in the `Entries` must be unique.
+- The `Entries` must be lexicographically ordered based on the `Key`.
 - `Entries Count` must be at least `1`.
 - The serialized size of the map, consisting of the serialized size of `Entries Count` plus the serialized size of all
   `Entries`, must not exceed `8192` bytes.