Change render group rendering algo

assets/shaders/Image-Instanced-Fat.vert

assets/shaders/Texture-Fat.frag

assets/textures/Cube_Blue_Outlined.png

assets/textures/Cube_Test.png

imgui.ini

source/engine/graphics/back/shaders/Program.cpp

source/engine/graphics/back/shaders/Program.hpp

source/engine/graphics/back/textures/Texture.cpp

source/engine/graphics/back/textures/Texture.hpp

source/engine/graphics/front/Engine.cpp

source/engine/graphics/front/Engine.hpp

source/engine/graphics/front/Renderer.cpp

source/engine/graphics/front/Renderer.hpp

source/engine/graphics/front/group/ImageGroup.cpp

source/engine/graphics/front/group/ImageGroup.hpp

source/engine/graphics/utility/isometric_sorter.cpp

source/engine/graphics/utility/isometric_sorter.hpp

source/engine/graphics/utility/reference_sorter.hpp

source/engine/graphics/utility/reference_sorter.tpp

source/main.cpp