Add Item List Compression

[programmerjake]

Add i3-style item list compression in the list of all known items where all items of a particular kind (e.g. all colors of wool block) are combined together into one item that you can click on to re-expand into the full list.

This is useful so you can quickly look through the list of all items without having to go through like 50 pages of moreblocks items, such as when using underch with moreblocks so there's tons of types of stone, each of which has dozens of slab/stair/etc. variants.