Toncenter API supported hash of a normalized external message

API V3 (Index):

- hash_norm field added to the Message structure. If the field is not present, it means this message is not an external message, or the normalized hash_norm is equal to the regular hash.

- All methods with msg_hash parameter search also by normalized hash.

API V2:

- api/v2/sendBocReturnHash returns the normalized hash in addition to the normal hash.