Mostly bug fixes. Some minor quality of life changes too

Changelog:

• fixed Bernie hitchance errors for older saves
• invisibility can no longer be unlearnt
• character locations now support rollback again #python 3 broke this
• player's inventory has been changed to a regular dictionary
• fixed gallery entries disappearing after filtering
• Iroha's name is now properly concealed during initial meeting
• added missing Bernie Underworld animations to Android version
• battle: changed 'select player' to 'select target' when targeting allies
• Willow will now tell the player to come back later if alchemy recipes aren't ready yet
• ghosts are now immune to osteoporosis
• Underworld hints will now close when interacting with the map
• fixed Underworld combat corpse generation
• fixed issues with summoning stuff in buff screen
• undead minions now disappear 90% slower when traveling in the Underworld
• fixed undead minions causing errors when disappearing after combat
• consume corpse is now useable outside combat
• fixed the player being able to skip Underworld encounters
• corpses now persist after combat
• fixed player's missing phone social media icon