input: Introduce basic hyprland HID classes

Implements an intermediary HID class for mice, keyboards and touch devices, removing the old structs from WLClasses.hpp

Yes, virtual ones are duplicated a bit, but will likely be de-duped once wlr_input_device is not used anymore.

src/devices/IPointer.cpp

@@ -0,0 +1,5 @@
+#include "IPointer.hpp"
+
+uint32_t IPointer::getCapabilities() {
+    return HID_INPUT_CAPABILITY_POINTER;
+}