Update invui to 2.0

[LordIdra]

Invui is in alpha but will likely not be by the time we release. invui 2 is packet based which will resolve several current UI bugs

[JustAHuman-xD]

I would advise to wait till invui 2.0 comes out of alpha to switch over, as there are non insignificant changes each alpha version right now

[Seggan]

Done in #586