goModel doesn't work together with implements

If I generate resolvers for schema

```gql
interface SalesMetric {
order_count: Uint64!
revenue: String!
}

type TimeSalesMetric @goModel(model: "orderv1.SalesOverviewTimeResponse_Record") {
order_count: Uint64!
revenue: String!
milestone: String!
}
```

All works perfect

If I use implements

```gql
interface SalesMetric {
order_count: Uint64!
revenue: String!
}

type TimeSalesMetric implements SalesMetric @goModel(model: "orderv1.SalesOverviewTimeResponse_Record") {
order_count: Uint64!
revenue: String!
milestone: String!
}
```

It gives me an error:
```text
merging type systems failed: unable to bind to interface: /proto/order-service/v1.SalesOverviewTimeResponse_Record does not satisfy the interface /lib/model.SalesMetric
exit status 1
```