CapsuleServicePei

Produces the capsule PPI which currently only fully implements the CheckCapsuleUpdate functionality.

Everything else returns success or unsupported, as it is related to capsule coalescing.

This is needed as there is often infrastructure which detects FlashUpdate as a boot mode and attempts to find this PPI to check to make sure we actually have a capsule. So, we produce a simple PPI to satisfy that requirement.