New board: Elecrow CrowPanel Basic 2.8" (#225)

- Implemented Elecrow CrowPanel Basic 2.8"
- Change default "invert" setting for ILI934x driver from `true` to `false`
- Created `Xpt2046` driver subproject
- Refactored unPhone to use new `Xpt2046` driver subproject

Drivers/XPT2046/Source/Xpt2046Power.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <Tactility/hal/power/PowerDevice.h>
+#include <memory>
+
+using tt::hal::power::PowerDevice;
+
+/**
+ * Power management based on the voltage measurement at the LCD panel.
+ * This estimates the battery power left.
+ */
+class Xpt2046Power : public PowerDevice {
+
+public:
+
+    Xpt2046Power() = default;
+    ~Xpt2046Power() = default;
+
+    std::string getName() const final { return "XPT2046 Power Measurement"; }
+    std::string getDescription() const final { return "Power interface via XPT2046 voltage measurement"; }
+
+    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();