Add a rotary encoder

src/helpers/ui/RotaryInput.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <Arduino.h>
+
+enum class RotaryInputEvent : uint8_t {
+  None,
+  Next,
+  Prev,
+};
+
+class RotaryInput {
+public:
+  virtual ~RotaryInput() = default;
+
+  virtual bool begin() = 0;
+  virtual RotaryInputEvent poll() = 0;
+  virtual bool isReady() const = 0;
+};