boulder-va should explicitly record the quorum met for the issuance (eg, 5/6 or 6/6)

[mcpherrinm]

Per MPIC ballot, we should record this explicitly in audit logs.

We need to make sure that we can distinguish between a positive failure from an RVA versus not waiting longer for a response.

---

Notes added by @beautifulentropy

RVA audit logs are not collected to tape, we'll need to:

• [ ] Make remote perspective quorum configurable
• [ ] Return Perspective and RIR from RVA -> VA
• [ ] Log remote perspective quorum result
• [ ] Record gRPC timeouts and cancellations distinctly from validation failures
• [ ] During deployments and scaling actions, ensure all attempts dispatched by the VA -> RVA are completed and logged. Any timeouts in the graceful shutdown process should be longer than the VA -> RVA gRPC timeout.