Fix bug with preload hooks

[flibber-hk]

Repro: Install spicyrando from modlinks, which PreloadHook-s Fungus1_21

I'm pretty sure this is not the most correct fix but I don't really want to figure out the most correct fix, this works and is pretty fast.

Obviously the alpha/beta values can be improved but I didn't really want to do maths so I just split it 50/50

[flibber-hk]

I'm pretty sure this is not the most correct fix

To be clear I believe what is happening here is that:

• standard preloads are done with RepackScene
• preload hooks are done with FullScene

I think the ideal fix would do standard preloads with RepackAssets and preload hooks with RepackScene, or maybe everything with RepackScene in the same bundle? I don't know enough to implement a fix like this though

[fifty-six]

I'd say this needs like a more clear explanation in-line but I'd also want to split the stuff so that the stuff shared between objects and hooks gets only loaded the one time. I'll take a look at adjusting repacking for the hooks before though since that was mentioned.