GUI: Default font is limited in language support

[mistydemeo]

The default font in the builtin themes has limited Asian language support. I've been testing a large number of Japanese Director games for Director support, and the lack of Japanese font support makes the UI very difficult to use.

The Japanese font already shipped by ScummVM, NotoSansJP-Bold.otf, has support for Latin characters, Cyrillic, Greek, and hangul, so I've been using it as the default font in a custom theme I built. I think it would be worth investigating either whether the default theme can be changed or if it's possible to introduce fallback rendering that uses the other fonts to handle characters that aren't in the default.

I've attached an image of what it looks like to try to view any game with a Japanese or Chinese title in the game list, along with what it should look like.

[mistydemeo]

View with the default font

[mistydemeo]

View with Noto Sans JP