Define in json whether an object will have a hitregion

Right now, in Lätkäzombiet, several items are hardcoded to have no hitregion: tactic_board_wiper, tag_on_wall, marker, library_receipt, hairkeeper, all the showers.

There should be a flag in the object definition in the json which defines if the hitregion should be made or not.

It affects if the transparent part of the object's picture can be clicked or not: if the object has a hitregion, you can only click on the visible parts, otherwise you can click on a seemingly empty spot and still connect to the item.

Locate the JSON object definitions and the code that creates hitregions and handles clicks. Use the listed objects as regression cases, then verify that the new flag controls whether transparent image areas can be clicked while preserving each object's intended behavior.

Written by the indexing model from the issue text.