Deprecate one-off encryption of TxOutItems
Resolves #1632 (closed)
The encryption at rest of signed TxOutItems is not a meaningful security improvement.
This branch removes the encryption side, and changes decryption failures to fall through.
When it is determined that all bifrosts have no more leveldb entries that are encrypted at some point in the future, the handrolled encryption functions can be removed entirely.
Edited by Son of Odin