Memo encryption/decrypt feature using aes

Do upvote my post as encouragement of my work thanks! :) Will contribute more if you do so! I also did some explanation on how encrypt/decrypt works here https://peakd.com/hive-139531/@tngflx/contribution-to-dhive-added-memo-encryption-and-decrypt-feature

@good-karma Hi here is the one with isWif included. A corrected version.