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/SdCard.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <Tactility/TactilityCore.h>
+
+namespace tt::hal {
+
+#define TT_SDCARD_MOUNT_NAME "sdcard"
+#define TT_SDCARD_MOUNT_POINT "/sdcard"
+
+class SdCard {
+public:
+    enum class State {
+        Mounted,
+        Unmounted,
+        Error,
+        Unknown
+    };
+
+    enum class MountBehaviour {
+        AtBoot, /** Only mount at boot */
+        Anytime /** Mount/dismount any time */
+    };
+
+private:
+    MountBehaviour mountBehaviour;
+
+public:
+    explicit SdCard(MountBehaviour mountBehaviour) : mountBehaviour(mountBehaviour) {}
+    virtual ~SdCard() = default;
+
+    virtual bool mount(const char* mountPath) = 0;
+    virtual bool unmount() = 0;
+    virtual State getState() const = 0;
+
+    virtual MountBehaviour getMountBehaviour() const { return mountBehaviour; }
+    bool isMounted() const { return getState() == State::Mounted; }
+};
+
+} // namespace