GET_CONVAR and GET_CONVAR_INT client side

[SaltyGrandpa]

Perhaps client-side convars are already planned, per the new Configuration & Input documentation:

@vanadium

A good first step would be replacing the entire configuration persistence system (settings.xml and ‘profile settings’ such as the non-graphical options in the game settings menu) with a few convars bound to the raw setting structures. These would then be saved to a Quake-style config.cfg file automatically by means of implementing the Archive flag.

Nevertheless, I would love to see this be implemented.