added shooting

src/game/CMakeLists.txt

src/game/game.cpp

src/game/game.h

src/game/input/events.hpp

src/game/input/sdl_input.cpp

src/game/multi_shot.cpp

src/game/multi_shot.h

src/game/renderer/sdl_renderer.cpp

src/game/renderer/sdl_renderer.h

src/game/shoot_controller.cpp

src/game/shoot_controller.h

src/game/single_shot.cpp

src/game/single_shot.h

src/game/state/entities.cpp

src/game/state/entities.h

src/game/state/shooter.cpp

src/game/state/shooter.h