Move BufferUse, BufferVertexAttribDefinition and VaoLayout from Framework to Core
Make Core's CMakeLists.txt produce a library
Adapt BufferUse, BufferVertexAttribDefinition and VaoLayout to Core
VaoManager uses VaoLayout from Core
Add test for VaoLayout
Renamed SceneManager to SceneSystem
Rename type and name of some variables related to SceneSystem
Moved BufferManager from Utilities to Managers
Make Managers be built
Move ShaderManager from Utilities to Managers
Move TemplateManager from Utilities to Managers
Move VaoManager from Utilities to Managers