Dynamically load assets to reduce main binary size

[KonaeAkira]

All assets are currently compiled into the main binary. Because of this, all assets are re-downloaded every time Raphael updates.

Assets that rarely change should be separated from the main binary to enable caching to reduce download size.

First step:

• [ ] Fonts
• [x] Images

Second step:

• [ ] Item data
• [ ] Recipe data

Item and recipe data should have FFXIV's patch number in their filenames to quickly invalidate cached data on updates.