TactilityC improvements (#359)

- Expose HAL Configuration's `UiScale`
- Updated docs
- Fix for `tt_timer_alloc()`
- Changed `enum class` to regular C `enum`
- Renamed enums (add prefix)
- Include `<stdbool.h>` where needed

TactilityC/Include/tt_hal.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Affects LVGL widget style */
+enum UiScale {
+    /** Ideal for very small non-touch screen devices (e.g. Waveshare S3 LCD 1.3") */
+    UiScaleSmallest,
+    /** Nothing was changed in the LVGL UI/UX */
+    UiScaleDefault
+};
+
+/** @return the UI scaling setting for this device. */
+UiScale tt_hal_configuration_get_ui_scale();
+
+#ifdef __cplusplus
+}
+#endif