Add FingerprintProofVerifier, a proof verifier that checks against a predefined set of certificate fingerprints. This will be used to implement <https://wicg.github.io/web-transport/#dom-quictransportconfiguration-server_certificate_fingerprints>. PiperOrigin-RevId: 314717008 Change-Id: I0a745f442618936c501e6324382c95806af369bb