Adds gRPC health check support

[KunxiSun]

• Introduces Check.grpc(...) to configure a gRPC health check for Consul, with optional TLS, timeout and deregistration.
• Maps parameters to Consul health check fields, including:
  • required: grpc (URL) and interval
  • optional: grpc_use_tls, tls_skip_verify, timeout, DeregisterCriticalServiceAfter
• Adds extensive unit tests covering various combinations of TLS, timeout, and deregistration to ensure correct dict output.
• Aligns with Consul's gRPC health check protocol and expected configuration structure.

[mbrulatout]

Thanks for the PR !
This made me realize this place would need quite a bit of work to add multiple other args to the various HC 😅