Firmware Install, All Options should sort versions from higher to lower

[rmackay9]

The Firmware Install, All Options screen allows users to install older versions of AP onto their autopilots. They most often want to pick a recent stable version so it would be best if the "Version Type" drop-down was formatted to reflect this.

So Stable versions would appear first and with higher numbers appearing higher in the list. Next would be Beta and then finally Dev. We should also consider removing the "Official" entry completely because it doesn't offer any versions that aren't already available as "Stable".

FYI @tridge

[EosBandi]

Ordering is easy.... but since it uses the https://firmware.ardupilot.org/manifest.json.gz, shouldn't we remove the OFFICIAL tagged items from there, instead of hacking the GUI to ignore them ? Is there any difference between OFFICIAL and STABLE ? Also there are some funny things going on with beta, there are still BETA-4.3.8....