Supreme: HamSandwich format doesn't handle changed items

[MirrorAzure]

Description

When saving world in hamsandwich format, all changes made in base items don't save.

Expected behavior

Hamsandwich format should save changed base items as well as it does with new items.

Actual behavior

Only new items are saved, but all changes made in base items are withdrawn.
However, world files saved in legacy supreme format stage those changes.

Steps to reproduce

1. Create new world;
2. Change base item;
3. Save world in Hamsandwich format;
4. Load saved world.

There is item_definitions section in new format, and it doesn't contain changed items data.

test_world.dlw

test_world.dlw_old

Possible reasons

The problem is probably in world2.cpp:

	for (int i = NUM_ORIGINAL_ITEMS; i < NumItems(); ++i)
	{
		item_definitions.write_string("");  // savename not yet implemented
		SaveItem(&item_definitions, GetItem(i));
	}

ref:
https://github.com/SpaceManiac/HamSandwich/blob/84f4b945165f134a7686f595be57fd096c2891ac/source/supreme/world2.cpp#L370C1-L374C3

We're only iterating through items which ids are between NUM_ORIGINAL_ITEMS and NumItems(), which are new added items.

Legacy saving method is using SaveItems function which handles cases when items were changed by player.

	changedItems=numItems-NUM_ORIGINAL_ITEMS;
	for(i=0;i<NUM_ORIGINAL_ITEMS;i++)
	{
		// has this item been modified in some way?
		if(memcmp(&items[i],&baseItems[i],sizeof(item_t)))
			changedItems++;
	}

ref:
https://github.com/SpaceManiac/HamSandwich/blob/84f4b945165f134a7686f595be57fd096c2891ac/source/supreme/items.cpp#L1075C1-L1081C3