New Sky/Atmosphere model in 4.24

[jrapczak]

@SebHillaire

@jrapczak If you want it, I would recommend you should grab those CLs (in order of integration):

1- Transform CL https://github.com/EpicGames/UnrealEngine/commit/59bebaba30a59cfefdf603926f2f3f186ff625d5
2- Some renaming https://github.com/EpicGames/UnrealEngine/commit/7494cdf3e24de16db815b84af20df3eb90db078b
3- Some bug fixing https://github.com/EpicGames/UnrealEngine/commit/345d7bb36ad6e1d0c51c342a59795da3afb6d3f7

Note: I may have dome other work in between those CLs…

Cool just found those in P4. Thank you!!!