Attestation config format

[rvolosatovs]

In #107 a multitude of X and X_blacklist fields are added and not all of these are consistent.

How about we have [deny] and [allow] sections instead?

E.g.:

[sgx.allow]
hash = "DEADBEEF"
signer = "BEEFDEAD"

[sgx.deny]
signer = "C0FFEE"

[rjzak]

• How would this look in code? Is this a simple Serde rename?
• What about other items in SGX and SNP? Would it be like below, and is that too many [sections]?:

[sgx.allow]
hash = "DEADBEEF"
signer = "BEEFDEAD"

[sgx.deny]
signer = "C0FFEE"

[sgx]
features = ["Debug", "ProvisioningKey", "EInitKey", "KSS"]
enclave_security_version = 0
enclave_product_id = 0