Adjust first four projects to use new rendering from buffers

projects/bindless_textures/resources/shaders/shader.frag

projects/bindless_textures/resources/shaders/shader.vert

projects/bindless_textures/src/main.cpp

projects/first_mesh/assets/shaders/shader.vert

projects/first_mesh/src/main.cpp

projects/first_scene/assets/shaders/shader.frag

projects/first_scene/assets/shaders/shader.vert

projects/first_scene/src/main.cpp

projects/first_triangle/src/main.cpp

projects/head_demo/assets/shaders/shader.geom

projects/head_demo/assets/shaders/shader.vert

projects/head_demo/assets/shaders/wired.geom

projects/head_demo/src/main.cpp