Gas Exoplanets

[evandorf]

With the removal of certain gas isotopes from the atmospheres of existing exoplanets (https://github.com/Aurorastation/Aurora.3/pull/22509), we should add gas planets to allow for the extraction of these resources. 

Hurdles to overcome:

- How to map the “ground”: my first idea would be that the general turf would be open air, like the rooftop holoprojection. It would need to be decided how dangerous these planets would be, since I would assume falling into the skies would be a quick descent into the high pressure gasses and death. You could try to overcome that with mandatory jet packs on these missions, but I’m open to ideas if you want to make it safer.

- I’m not sure if the gas isotopes were removed because of planetary fires or they were not balanced or lore accurate or something. If they are meant to be no longer an option for resource extraction, let me know.

I'm sure I'm missing some things so feedback is welcome.