[Tests] Add tests for CCoins deserialization
[Tests] Add tests for CCoins deserialization

Backports bitcoin/bitcoin 1e44169f0e0c334a86b14a22ebc8fec45cec7354
Mrs-X/Darknet,Mrs-X/PIVX,Mrs-X/Darknet,Mrs-X/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,Darknet-Crypto/Darknet,Mrs-X/Darknet,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Mrs-X/Darknet,Mrs-X/PIVX,Mrs-X/PIVX,Darknet-Crypto/Darknet,Mrs-X/Darknet,PIVX-Project/PIVX,Mrs-X/PIVX,Mrs-X/PIVX,PIVX-Project/PIVX,Mrs-X/Darknet,Darknet-Crypto/Darknet,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,PIVX-Project/PIVX