Add romanized name field to players

Fixes issue #193 by adding a field for a romanized version of the name.

~~Note that most korean names already are romanized, we should perhaps move those from `name` to `romanized` by some sort of regex/char recognition.~~ (Added as second commit) The `0018` migration script does this for the Chinese players with the format `RNAME (NAME)`, e.g `Lei Wang (王磊)`.