Editor: Rename Editor class to EditorWidget
Editor: Rename LayerSettings to LayerSettingsDialog
Editor: Rename LayerTab to LayerTabWidget, rename source files of LayerWidget to match new naming convention
Editor: Rename source files of SFMLWidget to match new naming convention
Editor: Rename source files of TileWidget to match new naming conventions
Editor: Update header guards  of LayerWidget.hpp, SFMLWidget.hpp
Rename collision.h to collision.hpp to match existing naming convention