Check loading modoptions from game archive

[sprunk]

BAR has this mumbo-jumbo to load modoptions from game archive.

https://github.com/beyond-all-reason/BYAR-Chobby/blob/b9b4cf731c69787aca25c3c944cd4b2d334892bb/LuaMenu/widgets/gui_modoptions_panel.lua#L659-L675

It would be nice if we didn't have to make sure the chobby list matches the gameside one. Caveats that BAR gets to avoid because they don't support mods at all:

• if you are playing a mod, the base ZK archive will be loaded but overwritten by the mod. Then if you F11 and try to set up a base ZK game it will display the mod's modoptions. I don't think this is fixable without engine changes.
• what if you join a room hosting a mod, it hasn't yet downloaded and you click the modoptions tab? Workable around with some sort of "downloading, please wait", and is probably not really a regression since chobby doesn't know about mods' modoptions anyway.