Implement M5Stack Cardputer + minor Tactility improvements (#331)

- Implement M5Stack Cardputer: display, SD card and keyboard
- `St7789Display` now supports a "gap" configuration
- `ElfApp` has improved errors

Boards/M5stackCardputer/Source/devices/CardputerEncoder.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <Tactility/hal/encoder/EncoderDevice.h>
+
+#include "keyboard/keyboard.h"
+
+/**
+ * Wrapper around the keyboard that uses the following buttons to simulate an encoder:
+ * - Up
+ * - Down
+ * - ok (fn + enter)
+ */
+class CardputerEncoder final : public tt::hal::encoder::EncoderDevice {
+    KEYBOARD::Keyboard keyboard;
+    int lastKeyNum = 0;
+    lv_indev_t* _Nullable lvglDevice = nullptr;
+
+    static void readCallback(lv_indev_t* indev, lv_indev_data_t* data);
+
+public:
+
+    std::string getName() const override { return "Cardputer Encoder"; }
+    std::string getDescription() const override { return "Cardputer keyboard up/down acting as encoder"; }
+
+    bool startLvgl(lv_display_t* display) override;
+    bool stopLvgl() override;
+
+    lv_indev_t* _Nullable getLvglIndev() override { return lvglDevice; }
+};