Modify painting name and tooltips, and create unique textures for each painting item

[Andrew6rant]

If CIT Resewn is installed, each painting will have a unique texture:

Tooltips are condensed down to one line.

Before:

After:

I'm marking this as a draft because my tooltip code isn't the cleanest

[Estecka]

I'll move the thumbnails to the minecraft namespace. I think it makes more sense since those are extensions of vanilla items, and people could theorically make those changes without using the mod.

For the tooltip, I'd prefer having the size on the left side. That way it won't change position depending on the preceding text, and should be easier to find at a glance :

2x2 Painting (The Stage is Set)
Kristoffer Zetterstrand

or simply

2x2 The Stage is Set
Kristoffer Zetterstrand

[Estecka]

I made the change to have the size on the left of the author. Other than that the code looks good to me.

[Andrew6rant]

Looks good to me! I do like the size on the left much better, thanks. The only thing I changed was a bit of indent in DecorationItemMixin, to make it clearer that the tooltip.add call is not inside of the if statement

[Andrew6rant]

Whoops! I committed to the wrong branch. (since it is a different feature, I thought it best to PR separately)

[Estecka]

Yeah, go make a separate branch and PR with those change. I'll revert it back to b6f4854 later before merging.