Core: make state.prog_items a Dict[int, Counter[str]]

[alwaysintreble]

What is this fixing or adding?

Changes CollectionState.prog_items from a Counter[Tuple[str, int]] to a Dict[int, Counter[str]], offering more speed.

How was this tested?

Generated 1000 world messenger multiworld 10 times before and after and saw a ~9% speed increase. Could use more testing and benchmark numbers, but this should increase generation speed overall.

[el-u]

Stardew Valley overwrites prog_items here:
https://github.com/alwaysintreble/Archipelago/blob/ada70d32963db68ad023811778d23e750c6b5017/worlds/stardew_valley/test/TestRules.py#L27
I don't know why it does that, but if you change it to overwrite it with a new dict-of-counter it should start working.

[alwaysintreble]

I don't know why it does that

I think it's testing that the starting inventory is properly required? But yeah it'd be a lot better to just test that with a clean state instead of telling the state to do things that will never happen in normal circumstances.

[LegendaryLinux]

Tested a generation and connected with ArchipIDLE, so I approve the IDLE change.

[Jarno458]

Tested it, it does seem to work, and does make debugging simpler