Handle `wasi:cli/run` specially for a command component

Right now if a command component is created and a world is included via:

```wit
package example:demo

world demo {
include wasi:cli/command
}
```

then the output component will expect a `Component` which implements the `wasi:cli/run` interface. This is already implicitly created for the "command" flavor of the component and the adapter, though, so could this world be modified in this situation implicitly by `cargo component` to avoid the requirment that `impl Guest for Component` is needed to compile?