[Feature Request] Change display of game size vs. disk space left to GiB

[MultisampledNight]

Is your feature request related to a problem? Please describe.
Currently, if upon installation there's not enough space left on disk, legendary displays the game size and how much space is left on disk in MiB. While it is technically correct, it's not too useful if you want to know how much space you'd need to clean up for ARK, for example.

Describe the solution you'd like
I think displaying game size and space left on disk in GiB will be much more obvious to most users.

Describe alternatives you've considered
None yet. legendary could additionally show how much space would need to be freed in order to install the game, but again that's not too useful with MiB imo.

Additional context
I'm actually coming from Rare and have been told the message about disk space < game size comes from legendary. Maybe the function responsible for returning the failure message could return a printable class which can be examined for details.