Web sequences don't seem to be supported

Web sequences seemingly always return:

```json 
{"error":"The requested resource does not exist."}
```

This is because in the plugin today, for web actions we only invoke if there is no sequence found. See https://github.com/adobe/aio-cli-plugin-app-dev/blob/main/src/lib/run-dev.js#L525

I am not sure if this is a bug or an intentional thing, but documenting this issue so its known