No more corpse of holding

[Fris0uman]

Summary

Bugfixes "Corpses can't be used as bag of holding anymore"

Purpose of change

• Let the squirrels rest in peace
• Corpses can't be used as bag of holding anymore

Describe the solution

• Monster with no loot to drop did not get their pocket set to disallowed so first fix that
  - [ ] Fix allowed not being saved or loaded(?) properly
• Move allowed to pocket_data so we don't need to save and load it and rename it forbidden
• Add more check for is_corpse and is_forbidden to not display pocket info when not necessary
• Add more check fr is_forbidden to make sure we can't stuff in there when grabbing items of the ground
• fix AIM max volume displayed
• Force insert item in corpse at mapgen

Describe alternatives you've considered

Since we're using force_insert_item to put the loot into corpses, we could make that pocket be 0 ml and 0 g and get rid of the rest of the implementation, no need for a allowed variable in that case or for extra checks. But 0 volume and 0 weight pocket do generate a bunch of error on load

Testing

• Kill zombie > loot is in the zombie and there's no erro
• let it revive > loot is in the zombie
• re kill the zombie > no error and loot is in the zombie
• one more cycle > no issue
• wield a squirrel corpse > no extra volume/length/weight capacity displayer inth g picksu menu or in AIM menu
• try to grab a halberd with g > no room to put it
• tryo to grab it with AIM > no room either
• save and reload > zombie still has its loot

Additional context