Guard against future web feature schema changes

# Background

From @past on this [PR](https://github.com/GoogleChrome/webstatus.dev/pull/509)
> Can you guard against future schema changes via assertions or similar? It's better to not display any information if the schema has changed than to silently ingest unexpected data.

The data could lead to use returning things like this from the features API:

```json
...
{
"feature_id": "features",
"name": ""
},
{
"feature_id": "groups",
"name": ""
},
{
"feature_id": "snapshots",
"name": ""
}
...
```

# Definition of done
- [ ] Add a validate helper that is called inside the Parse method for the web feature data.json https://github.com/GoogleChrome/webstatus.dev/blob/6f069fcbd4af4034d7802e724cd225f9a54b2b5f/workflows/steps/services/web_feature_consumer/pkg/data/parser.go#L34-L44
- That validate method should do some additional checks to make sure the data is as expected. If not, return a new error.
- At a minimum, it should check that the names for each feature is not empty.