Add NO_DISPLAY vitamin flag, show non-nutritional vitamins as 'Other contents' in food information menu

[anothersimulacrum]

Summary

SUMMARY: Infrastructure "Add vitamin flags"

Purpose of change

Addresses #35917 (comment)
I was in the area, and saw that it would be easy to add a NO_DISPLAY flag, and thought that would be beneficial for the protein bars bad_food counter vitamin.

Describe the solution

Add a flags_ member to vitamins, of type std::set<std::string>.
Add a has_flag function to vitamins, which searches that set, and looks for the flag argument passed to it.
Add code to load flags from JSON into this set.

Add FOOD_VIT_EFFECTS iteminfo_part, which displays non VITAMIN type vitamins as Other contents
Also add a check when populating the string that will be output for both of those, and don't add vitamins with the flag NO_DISPLAY.

Describe alternatives you've considered

Converting vitamins to use generic factory, but I decided that would be a bit out of scope.

Testing

[Davi-DeGanne]

We might actually want to do a whole new line instead, because it's still kinda odd that it shows up in the "Vitamin" category when simplified nutrition is not active. E.g.:

Vitamins (RDA): Vitamin C (10%)
Other contents: Toxins (26%)

Just a suggestion, if you don't feel it's necessary, I'm not overly attached to it.

[anothersimulacrum]

Yeah, I considered that, but it's more work!
I'll see what I can do.

[Davi-DeGanne]

Again, if you don't get around to it, no big deal -- I think that at some point we will have to rethink whether it's appropriate to display toxins-type vitamins in descriptions at all, but not doing so would need some sort of balancing mechanism (perhaps a device that can test for them). And we could just deal with how to format the description entries at that point.

[anothersimulacrum]

Okay, added that - this should be ready to go.
The original post has been updated with changes as well.