Touch and display driver subsystems reworked (and more) (#302)

- Refactored `TouchDevice`: it can now start/stop LVGL separately, and it has an optional `TouchDriver` interface
- Refactored `DisplayDevice`: it can now start/stop LVGL separately, and it has an optional `DisplayDriver` interface
- Updated all boards and drivers for above changes
- LVGL can now be stopped and (re)started on the fly
- Fixed issues with restarting Gui and Statusbar services
- Refactored `Gui` service to be class and renamed `Gui` to `GuiService`
- Fixed `Statusbar` service: forgot to deregister one of the icons
- Updated `esp_lcd_st7701` to v1.1.3
- `lv_textarea_create()` now automatically registers the hardware keyboard hooks (by wrapping the function)
- Fixed and updated `tactility.py`
- Cleanup of a lot of code
- `BootInitLvglBegin` and `BootInitLvglEnd` are replaced by `LvglStarted` and `LvglStopped`.
- Introduced `tt::service::State` which is accessible via `tt::service::getState()` (and internally via `ServiceInstance`)
- Started replacing `#define TAG` with `constexpr auto TAG = "..";`

Tactility/Source/kernel/SystemEvents.cpp

@@ -38,16 +38,16 @@ static const char* getEventName(SystemEvent event) {
             return TT_STRINGIFY(BootInitUartBegin);
         case BootInitUartEnd:
             return TT_STRINGIFY(BootInitUartEnd);
-        case BootInitLvglBegin:
-            return TT_STRINGIFY(BootInitLvglBegin);
-        case BootInitLvglEnd:
-            return TT_STRINGIFY(BootInitLvglEnd);
         case BootSplash:
             return TT_STRINGIFY(BootSplash);
         case NetworkConnected:
             return TT_STRINGIFY(NetworkConnected);
         case NetworkDisconnected:
             return TT_STRINGIFY(NetworkDisconnected);
+        case LvglStarted:
+            return TT_STRINGIFY(LvglStarted);
+        case LvglStopped:
+            return TT_STRINGIFY(LvglStopped);
         case Time:
             return TT_STRINGIFY(Time);
     }