Add family candy icon

[hacknug]

This PR adds a custom candy image with the family candy colors next to the candy count. It uses only three images to generate the given candy icon using canvas every time the modal loads. The icon is generated at 256×256 (original source size) and then scaled down to 24×24 to make sure they look good (or at least waaaaaay better than they would if generated at 24×24 directly).

Most of the code was adapted from RMKane's candy experiment here: http://rmkane.com/experiment/pokemon/candy/index.html

This is how it looks like:

To-Do

• [ ] Get rid of those for loops
• [ ] Do some testing to make sure no candies use the wrong colors (they shouldn't but I did some things by hand, so…)

[vinnymac]

@hacknug very pretty 👍