[zPIV][Cleanup] Remove non-public zerocoin spend checks in ATMP
[zPIV][Cleanup] Remove non-public zerocoin spend checks in ATMP

Now that activation height has passed, remove
CheckPublicCoinSpendEnforced and simply reject any non-public zerocoin
spend in AcceptToMemoryPool, without doing any further validation.
PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Darknet-Crypto/Darknet,Darknet-Crypto/Darknet,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Darknet-Crypto/Darknet