avoid leakage through reputation lookup

[brenzi]

Our first naive design verifies reputation on Encointer's parachain using a (local) rpc node and storage proofs. The operator of the personhood oracle could sniff these lookups and learn the link between badges issued by the oracle and encointer accounts

This linkability can be avoided by replicating the entire reputation registry inside the enclave and performing lookups there. An intermediate option would be to mask the lookup with a ton of fake requests. This only protects privacy if fakes are accounts with the same reputation as the badge issued, so this option may be tricky to do