[UI] `[object object]` string output from query workbench advise

When attempting to build an index from an advised suggestion within the query builder, an error is displayed with [object object].

To reproduce

• Navigate to the query workbench
• Enter a query with a valid format, but an incorrect scope/collection.
• Using the beer-sample bucket. This query is missing the '_' from default.

```
SELECT name, brewery_id
FROM `beer-sample`.`default`.`_default`
WHERE brewery_id IS MISSING
LIMIT 2;
```

• Click advise, the results will suggest to create an index.
• Click the button to create an index, and the error will show.