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/app/display/Display.cpp

@@ -1,10 +1,12 @@
-#include "app/AppContext.h"
-#include "Assets.h"
-#include "DisplaySettings.h"
-#include "Tactility.h"
-#include "lvgl/Toolbar.h"
-#include "lvgl.h"
-#include "hal/Display.h"
+#include "Tactility/app/display/DisplaySettings.h"
+
+#include "Tactility/hal/Display.h"
+#include "Tactility/lvgl/Toolbar.h"
+
+#include <Tactility/Assets.h>
+#include <Tactility/Tactility.h>
+
+#include <lvgl.h>
 
 namespace tt::app::display {
 
@@ -13,7 +15,6 @@ namespace tt::app::display {
 static bool backlight_duty_set = false;
 static uint8_t backlight_duty = 255;
 
-static bool gamma_set = false;
 static uint8_t gamma = 255;
 
 #define ROTATION_DEFAULT 0
@@ -49,7 +50,6 @@ static void onGammaSliderEvent(lv_event_t* event) {
         int32_t slider_value = lv_slider_get_value(slider);
 
         gamma = (uint8_t)slider_value;
-        gamma_set = true;
 
         hal_display->setGammaCurve(gamma);
     }