Item piles grid

Rough draft of a grid-based inventory system thing - it can't swap positions of entries yet

Let's thread it

Right now I'm focusing on getting the bare bones working, it's too early to tell if I'll be about to get fancy with it. This is solely in item piles, and it will remain so.

Definitely keeping an eye on this effort as in the future quite possibly I can add a generic grid component to TRL / Svelte to accomplish this task so that something like this can be easily reused in any number of packages.

Wasp is using TRL / Svelte, but this particular effort right now is using a 3rd party library: svelte-grid-extended. IMHO the 3rd party library could use a few touch ups to work better in general and then a potential reusable TRL component could be made rather than a one off implementation in Item Piles.. That would of course more or less require TRL / Svelte to be used, so unless other packages are also made w/ Svelte / TRL the likelihood to be included by an App v1 / stock Foundry package is probably not going to happen.

Not by me, but someone else is free to give it a shot