core: frontend: version chooser and firmware services surprisingly slow to load

### Current behaviour

These pages don't seem to get very much information, but it seems to take a long time for them to load, which can be frustrating. The current spinning logo is definitely better than nothing.

### Expected or desired behaviour

Either somehow reduce the time between "user requests information" and "information appears" (i.e. fetch or process faster), or display the options one at a time as they get returned. The primary issue is the _feeling_ of "nothing is happening", although reducing unnecessary waiting time where possible is always a benefit.

### Prerequisites

- [X] I have checked to make sure that a similar request has not already been filed or fixed.