ItemListSelector source commenting and that TODO transpiler

[kpqi5858]

While I making compatibility patch for Toggleable Readouts 260f769, I found that codebase is not good.

As I had said before(#2), I can't work on RimWorld modding currently.

[kpqi5858]

Actually not that bad. It just needs a bit more commenting and transpiler (or better implementation) for Patch_RecourceReadout

[kpqi5858]

Using a whole ThingFilter for resource readout filtering might be a bad idea. It caused incompatibles like CustomThingFilters. Toggleable Resources' solution is probably better.