Support for multiple server certificates

Describe the feature you'd like supported

Currently MsQuic only supports a single QUIC_CERTIFICATE_HASH_STORE in QUIC_CREDENTIAL_CONFIG, so servers cannot offer both RSA-based and ECDSA-based ciphers. As certificate protocols evolve it would be useful to support multiple types of certificates simultaneously.

Proposed solution

QUIC_CREDENTIAL_CONFIG.CertificateHashStore is already a pointer type. Either accept an array length via the Reserved parameter, or create a new QUIC_CERTIFICATE_MULTI_HASH_STORE type to handle an array of hash store objects.

Additional context

No response