Registration of the Input Verification Service

In cases where inputs are private, the Generator Image contains the input verification logic. As the Generator Image itself runs inside a secure enclave, attestations from a whitelisted Generator Image (which will normally be run by the Generator itself) claiming that inputs are wrong are considered valid by the Input Verifier.

However, when the inputs are public and Generators are not required to run in enclaves themselves, someone is required to run the Input Verification Service.