Follow-up for GCP destination loading

The following discussion from !124384 (merged) should be addressed:

• @lorenzvanherwaarden started a discussion: (+1 comment)

  thought (non-blocking): an idea for a follow-up issue is that the isLoading would use an "or" instead of "and" and it both shows the destinations (either HTTP or GCP logging) which have been fetch already and the loading spinner, so you know there are still results to come in. Now, if either of the destinations are loaded, it shows the results without loading, and later the list updates. 🙂