Pokémon R/B: Allow generating with all items linked

[Alchav]

What is this fixing or adding?

Allows games with all items linked to generate. Stores an item outside the item pool to place into the Player's PC, as this location cannot have a non-local item in it for technical reasons. The rest of the usual "forced local" items allow item linked items for the player, though this defeats the purpose of forcing them to be local items.

How was this tested?

Generated with a default yaml + "Everything" item linked. Ran the #2081 test, SMZ3 reported failure but not Pokémon R/B.

[Exempt-Medic]

One small comment that probably doesn't need to be addressed. Otherwise the changes seem fine, tested various configurations locally and they worked.

[qwint]

changes to init look good, tested a simple item link (with skip output so did not play) with mostly default settings locally, did not review regions.py changes past the section affecting world.pc_item, but from a skim the rest just looks like reorganization

[Exempt-Medic]

changes to init look good, tested a simple item link (with skip output so did not play) with mostly default settings locally, did not review regions.py changes past the section affecting world.pc_item, but from a skim the rest just looks like reorganization

Yeah the regions.py changes need to be reverted

Waiting on regions.py update

[Exempt-Medic]

You reverted all the file changes btw

[Exempt-Medic]

@Alchav Reminder about this PR