* AKPublic.Verify: Return an error if a provided PCR of the correct
   digest was not included in the quote.
 * AKPublic.VerifyAll: Implement VerifyAll method, which can cross-check
   that provided PCRs were covered by quotes across PCR banks.
 * PCR.QuoteVerified(): Introduce getter method to expose whether a
   PCR value was covered during quote verification.