Validate that Connect Native services define a port

[oulman]

This PR adds a validation check for PortLabels on Connect Native enabled services. This is a requirement in Consul and if missing from the job spec will continually error.

"service": "nomad",
"message": "failed to update services in Consul",
"attributes": {
    "hostname": "<snip>",
    "@level": "warn",
    "@timestamp": "2024-10-29T15:16:34.148322Z",
    "service": "nomad",
    "@module": "consul.sync",
    "error": "Unexpected response code: 400 (Validation failed: 1 error occurred:\n\t* Port or SocketPath must be set for a Connect native service.)",
    "status": "info",
}

I can't get all of the tests to pass locally but TestService_Validate looked good.

=== RUN   TestService_Validate
=== PAUSE TestService_Validate
=== CONT  TestService_Validate
=== RUN   TestService_Validate/base_service
=== RUN   TestService_Validate/Native_Connect_without_task_name
=== RUN   TestService_Validate/Native_Connect_with_task_name
=== RUN   TestService_Validate/Native_Connect_without_port
=== RUN   TestService_Validate/Native_Connect_with_port
=== RUN   TestService_Validate/Native_Connect_with_Sidecar
=== RUN   TestService_Validate/provider_nomad_with_checks
=== RUN   TestService_Validate/provider_nomad_with_invalid_check_type
=== RUN   TestService_Validate/provider_nomad_with_tls_skip_verify
=== RUN   TestService_Validate/provider_nomad_with_connect
=== RUN   TestService_Validate/provider_nomad_valid
=== RUN   TestService_Validate/provider_consul_with_notes_too_long
--- PASS: TestService_Validate (0.00s)
    --- PASS: TestService_Validate/base_service (0.00s)
    --- PASS: TestService_Validate/Native_Connect_without_task_name (0.00s)
    --- PASS: TestService_Validate/Native_Connect_with_task_name (0.00s)
    --- PASS: TestService_Validate/Native_Connect_without_port (0.00s)
    --- PASS: TestService_Validate/Native_Connect_with_port (0.00s)
    --- PASS: TestService_Validate/Native_Connect_with_Sidecar (0.00s)
    --- PASS: TestService_Validate/provider_nomad_with_checks (0.00s)
    --- PASS: TestService_Validate/provider_nomad_with_invalid_check_type (0.00s)
    --- PASS: TestService_Validate/provider_nomad_with_tls_skip_verify (0.00s)
    --- PASS: TestService_Validate/provider_nomad_with_connect (0.00s)
    --- PASS: TestService_Validate/provider_nomad_valid (0.00s)
    --- PASS: TestService_Validate/provider_consul_with_notes_too_long (0.00s)
PASS

[gulducat]

Thanks for the PR!

For posterity, since the error said "Port or SocketPath must be set", I double-checked SocketPath. It doesn't look like there's any such option in Nomad for that in this context, so it's Port or bust, and this very nicely busts much earlier, at job submit time. 👍