Update global link art for OR/AS.

Mainly new mega forms from OR/AS, but also:

- Cosplay Pikachu forms
- Mawile(!?)
- Primal Groudon & Kyogre
- Hoopa
- Volcanion

The image for uncostumed Cosplay Pikachu is identical to the normal
Pikachu, so is omitted.

Hoopa and Volcanion were probably available before OR/AS, but
whatever. Now we have them.

Mawile has a new image. Dunno why. All the other images are exactly the
same as before.

Downloaded with https://github.com/magical/pdw/blob/master/pgl_get.go
Compressed with optipng and advdef -z3.