Distinct food court icon

[wmisener]

PR #1153, which added restaurants, also rendered food courts (amenity=food_court) with the same restaurant knife-and-fork icon. But food courts aren't exactly restaurants: they contain restaurants. In a sense, to dust off my SAT analogies, a restaurant is to a food court like a bus stop is to a bus station. Thus, I propose a food court icon that is the restaurant icon inscribed in a circle, following the logic Americana has already taken in #845 for bus and train stations.

Old:

New:

One slightly unfortunate aspect is that I had the fork and knife icon is pretty much 20x20, so I had to shrink them a bit to fit within a 20px diameter circle. So the utensils appear a bit smaller in the food court icon than in nearby restaurant icons, but hopefully the circle's added prominence makes up for it. I guess one possible solution would be to shrink the restaurant icon so that it's not 20x20 (some icons aren't, like bus stops), but I don't know that it's necessary just for this.

The icon appears at z15, one before restaurants. It can show up without a label at that zoom, like supermarkets and gas stations. (Side note: which icons do and don't appear without labels at certain zooms is still quite ad hoc, the style would probably benefit from some stated logic for it)

More samples:

Funnily enough, the food court icon would now be the first POI that shows up in the style for many large malls. I don't think that's a flaw per se, but rather a sign that things like malls and department stores should probably be fairly high priorities for POIs the project should tackle.