Avalonia HUD Replacement

The game's old, slow, and ugly HUD based on Scaleform GFx is replaced with a new HUD based on Avalonia which is built with modern design principles and performance in mind. The Avalonia HUD is integrated into the game by way of a custom Avalonia platform that uses Win2D to integrate into the game's rendering swap chain.

Besides improved usability and performance, this also gives us more freedom to modify the HUD in whatever way makes sense for TERA Arise.