Fixes and improvements (#620)

- Standardized keyboard input using Unicode-based key codes across supported devices and the simulator. Keyboards don't emit `LV_KEY_*` anymore.
- Refactored lilygo encoder driver into a reusable GPIO rotary encoder driver (see `Drivers/gpio-encoder-module/`). Added more features to the config file.
- Improved LVGL keyboard device management, including duplicate prevention and reliable reconnects.
- LVGL file mutex now registers with lvgl start/stop
- Improved LVGL startup/shutdown stability and memory allocation reliability.
- Increased simulator LVGL memory capacity and improved USB device-class handling.

Drivers/gpio-encoder-module/source/module.cpp

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver gpio_encoder_driver;
+
+static Driver* const gpio_encoder_drivers[] = {
+    &gpio_encoder_driver,
+    nullptr
+};
+
+Module gpio_encoder_module = {
+    .name = "gpio-encoder",
+    .drivers = gpio_encoder_drivers
+};
+
+} // extern "C"