Remove hacky argument based prefetcher

[jakmeier]

#7620 is a hacky way to make Sweatcoin workload faster until we have general optimizations ready. This hacky code is temporary and we want to remove it when we can. The expectation is that we can remove it after flat storage. (#7327)

Work plan:

1. Wait for flat storage.
2. Test performance for mainnet traffic, specifically Sweatcoin, with disabled argument based prefetcher.
3. If possible, remove arugment based prefetcher.
4. If 3. is not possible, instead come up with alternative, such as making the prefetcher more general and less hacky.