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`)

TactilityHeadless/Include/Tactility/hal/Power.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <cstdint>
+
+namespace tt::hal {
+
+class Power{
+
+public:
+
+    Power() = default;
+    virtual ~Power() = default;
+
+    enum class MetricType {
+        IsCharging, // bool
+        Current, // int32_t, mAh - battery current: either during charging (positive value) or discharging (negative value)
+        BatteryVoltage, // uint32_t, mV
+        ChargeLevel, // uint8_t [0, 100]
+    };
+
+    union MetricData {
+        int32_t valueAsInt32 = 0;
+        uint32_t valueAsUint32;
+        uint8_t valueAsUint8;
+        float valueAsFloat;
+        bool valueAsBool;
+    };
+
+    virtual bool supportsMetric(MetricType type) const = 0;
+
+    /**
+     * @return false when metric is not supported or (temporarily) not available.
+     */
+    virtual bool getMetric(Power::MetricType type, MetricData& data) = 0;
+
+    virtual bool supportsChargeControl() const { return false; }
+    virtual bool isAllowedToCharge() const { return false; }
+    virtual void setAllowedToCharge(bool canCharge) { /* NO-OP*/ }
+};
+
+} // namespace tt