Fixup SDKTools to not require byte sig or symbol to get g_pGameRules

It's probably easier to look at each commit individually.

Things are a bit messy, but SDKTools already is. One Day it will get refactored, but for now, no sense in lipstick on a pig.

I included gamedata for TF2 (uses name of gamerules datatable on gamerules proxy). I'll add others at some point.