Overview of the Issue

Two issues we have with HTTPRoute services is that we:

1. Seem to have failed to normalize the weight of a given service to 1 by default (it stays 0 if unspecified)
2. Additionally, when a service is skipped in our discoverychain construction code:

we can potentially wind up with no service splits (if we have no services with non-zero weight), and we fail to append a corresponding splitter here:

that winds up with our synthetic router referencing a service route for a splitter that doesn't exist:

and we wind up with envoy spitting out tcp/http mismatch protocol errors (due to the compiled discovery chain thinking that the referenced, non-existent splitter should be treated as a TCP-resolver discovery node).

Reproduction Steps

Create and attach an HTTPRoute with referencing two services in a routing rule where each has 0 weight, such as:

Rules = [
  {
    Services = [
      {
        Name = "service-one"
      },
      {
        Name = "service-two"
      }
    ]
  }
]

Attach to a gateway and watch Consul logs for protocol mismatch errors.

This should be fixed in two ways:

1. We should normalize to, Weight = 1, and
2. We shouldn't add a route to the router if no corresponding splitter was added.