Core: Add item.filler helper

[Exempt-Medic]

What is this fixing or adding?

Adds item.filler to go with item.advancement, item.useful, and item.trap

How was this tested?

Wasn't

[NewSoupVi]

I think this should be not (0b111 & self.classification) to leave the door open for filler_skip_balancing and to work with worlds that use their own custom flags

[Exempt-Medic]

I think this should be not (0b111 & self.classification) to leave the door open for filler_skip_balancing and to work with worlds that use their own custom flags

So the idea is that world-added flags can't change the "filler" status because filler is defined as a lack of trap/useful/progression? Thoughts on just being explicit with not (self.trap or self.useful or self.advancement) ?

[NewSoupVi]

I think this should be not (0b111 & self.classification) to leave the door open for filler_skip_balancing and to work with worlds that use their own custom flags

So the idea is that world-added flags can't change the "filler" status because filler is defined as a lack of trap/useful/progression? Thoughts on just being explicit with not (self.trap or self.useful or self.advancement) ?

I think I would say so. With the exception of trap ( :/ ), flags determine how core handles the item, and there is no way for a world to affect that with custom bits on the bitflag

[Exempt-Medic]

Marked for merge after hotfix window

~How am I actually going to remember which PRs I've "marked for merge"? I didn't think this through~

Marked for merge after hotfix window

~How am I actually going to remember which PRs I've "marked for merge"? I didn't think this through~

Add waiting on other tag