Move ShadowParamsUBO from 5 separate shadow rendering functions (2 in
m2_renderer, 1 in terrain_renderer, 1 in wmo_renderer) into shared
vk_frame_data.hpp header. Eliminates 5 identical local struct definitions
and improves consistency across all shadow pass implementations. Structure
layout matches shader std140 uniform buffer requirements.
Move ShadowPush from 4 separate rendering modules (character_renderer,
m2_renderer, terrain_renderer, wmo_renderer) into shared vk_frame_data.hpp
header. This eliminates 4 identical local struct definitions and ensures
consistency across all shadow rendering passes. Add vk_frame_data.hpp include
to character_renderer.cpp.
