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`)

TactilityC/Include/tt_lvgl_toolbar.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "tt_app.h"
+#include <lvgl.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Create a toolbar widget that shows the app name as title */
+lv_obj_t* tt_lvgl_toolbar_create(lv_obj_t* parent, AppHandle context);
+
+/** Create a toolbar widget with the provided title*/
+lv_obj_t* tt_lvgl_toolbar_create_simple(lv_obj_t* parent, const char* title);
+
+#ifdef __cplusplus
+}
+#endif