Project restructuring (fixes macOS builds) (#198)

- Create `Include/` folder for all main projects
- Fix some issues here and there (found while moving things)
- All includes are now in `Tactility/` subfolder and must be included with that prefix. This fixes issues with clashing POSIX headers (e.g. `<semaphore.h>` versus Tactility's `Semaphore.h`)

Tactility/Source/lvgl/Toolbar.cpp

@@ -1,10 +1,10 @@
 #define LV_USE_PRIVATE_API 1 // For actual lv_obj_t declaration
 
-#include "Toolbar.h"
+#include "Tactility/lvgl/Toolbar.h"
 
-#include "service/loader/Loader.h"
-#include "lvgl/Style.h"
-#include "Spinner.h"
+#include "Tactility/service/loader/Loader.h"
+#include "Tactility/lvgl/Style.h"
+#include "Tactility/lvgl/Spinner.h"
 
 namespace tt::lvgl {