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 = "..";`

Drivers/XPT2046/Source/Xpt2046Power.h

@@ -1,8 +1,8 @@
 #pragma once
 
 #include <Tactility/hal/power/PowerDevice.h>
-#include <memory>
 
+class Xpt2046Touch;
 using tt::hal::power::PowerDevice;
 
 /**
@@ -11,9 +11,13 @@ using tt::hal::power::PowerDevice;
  */
 class Xpt2046Power : public PowerDevice {
 
+    std::shared_ptr<Xpt2046Touch> xptTouch;
+
+    bool readBatteryVoltageOnce(uint32_t& output);
+    bool readBatteryVoltageSampled(uint32_t& output);
+
 public:
 
-    Xpt2046Power() = default;
     ~Xpt2046Power() = default;
 
     std::string getName() const final { return "XPT2046 Power Measurement"; }
@@ -22,10 +26,6 @@ public:
     bool supportsMetric(MetricType type) const override;
     bool getMetric(MetricType type, MetricData& data) override;
 
-private:
-
-    bool readBatteryVoltageOnce(uint32_t& output) const;
-    bool readBatteryVoltageSampled(uint32_t& output) const;
 };
 
 std::shared_ptr<PowerDevice> getOrCreatePower();