GET components for a topic returns wrong number of components

Imagine 2 components for topic id <id> with one component export control True.

```
GET /api/v1/topics/<id>/components returns 

{
  "_meta": {
    "count": 2
  }, 
  "components": [
    {...}
  ]
}
```

Count should correspond to the total of the components in the topic accessible to the user
ie `"count": 1`


