fix: apply various missing textures
feat: modified ApplyVertexColour and ApplyVertexColourTransparent shaders, the material surface attributes may now be overwritten
feat: implement OverlayShader for 'faking' vertex colours on certain external assets
feat: add main theme as mono disc
feat: add WS2_common_car model
feat: update lighting settings and skybox feel
chore: tweak various project settings
Signed-off-by: Jo <johannesreckers2006@gmail.com>