use ConVar for wire render toggle

[VDFOREVER]

Drawing wires can take up to 30 fps, I think it's worth replacing with ConVar to maintain the value

[bewflast]

those changes are not good for performance because :GetBool() is a way, way heavier than just do ~= 0 of a local variable

function Wire_Render is a hot-path code so i think there is a reason for a trick with local var which is modificated through console command instead of using convar abstraction