Give furniture max volume

Resurrected an old branch of mine.
Fixes #7095

Gives furniture a max_volume setting (loaded from json) which determines how much can be stored on/in that square.

The default value is -1 which is ignored (the normal MAX_VOLUME_IN_SQUARE setting applies here). The null-furniture and several others (like the bulletin board) have this.

This is supposed to mean that the furniture does not add storage space, nor does it obstruct the space on the floor.

Other furnitures like racks, dresser, bookcase have a setting that is above MAX_VOLUME_IN_SQUARE. Therefor one can store more items in a square if there is a specific furniture there.

Bonus: show maximal volume of vehicle parts and furniture/terrain in advanced inventory.

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Old rationale: some furnitures occupy the whole squre making it impossible to move onto it, they also add multiple storage areas. Putting all things one a flat square will eventually lead to a pyramid made of items, more items will than spill out of that square. But with additonal boards (like a crate), or multiple crates stacked above each other (or a dresser) one can put more stuff there.

Also what was said in #7095.

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Edit:
Today is not my day.

I removed that stupid -1 as placeholder for MAX_VOLUME_IN_SQUARE, each terrain/furniture has a specific `max_volume`. It defaults to MAX_VOLUME_IN_SQUARE if not specified in json.