Initial implementation of a core class object.

config/Sources.cmake

include/vkcv/Context.hpp

include/vkcv/Core.hpp

include/vkcv/Handles.hpp

include/vkcv/Window.hpp

projects/first_triangle/src/main.cpp

src/vkcv/Context.cpp

src/vkcv/Core.cpp

src/vkcv/CoreManager.cpp

src/vkcv/CoreManager.hpp

src/vkcv/Handles.cpp

src/vkcv/Window.cpp